Broken Hyperlinks

The following URLs no longer point to valid pages. The pages may have moved, or they may have vanished. Any assistance in providing additional information as to the current location of the following items would be greatly appreciated. Please send updates to the MathWorld team

AKS Primality Test: (2007-12-13) Indian Institute of Technology. "PRIMES is in P." http://www.cse.iitk.ac.in/news/primality.html

Barth Sextic: (2003-02-26) Dominici, P. "Flight Through Barth's Sextic." http://www.mi.uni-erlangen.de/~bauerth/flight/

Bell Number: (2026-05-16) Larrosa Canestro, I. "Bell(2841) Is Prime." Feb. 13, 2004. http://groups.yahoo.com/group/primenumbers/message/14558

Bernoulli Number: (2026-05-16) Oakes, M. "Re: Prime Bernoulli Numerators." primenumbers group. Feb. 11, 2004. http://groups.yahoo.com/group/primenumbers/message/14550

Cayley Graph: (2026-05-04) Royle, G. "Cayley Graphs." http://school.maths.uwa.edu.au/~gordon/remote/cayley/

Cayley Graph: (2026-05-04) Royle, G. "Transitive Graphs." http://school.maths.uwa.edu.au/~gordon/trans/

Chen Prime: (2026-05-16) Andersen, J. K. "Chen AP3 with 3074 digits." http://groups.yahoo.com/group/primeform/message/6381

Circle Packing: (2003-02-25) Nurmela, K. J. and Östergård, P. R. J. packings/square/. http://www.tcs.hut.fi/packings/square/

Combinatorics: (1999-12-06) Coolsaet, K. "Index of Combinatorial Objects." http://gonzo.hogent.be/~kc/ico/

Cousin Primes: (2026-05-16) Andersen, J. K. "Gigantic Sexy and Cousin Primes." Post to primeform user forum. Nov. 3, 2005. http://groups.yahoo.com/group/primeform/message/6637

Coxeter's Loxodromic Sequence of Tangent Circles: (2006-02-14) Coxeter, D. "Coxeter on 'Firmament.' " http://www.bangor.ac.uk/SculMath/image/donald.htm

Cycloid: (2003-02-25) Muterspaugh, J.; Driver, T.; and Dick, J. E. "The Cycloid and Tautochronism." http://php.indiana.edu/~jedick/project/intro.html

Diophantine Equation--6th Powers: (2003-02-25) Resta, G. "New Results on Equal Sums of Sixth Powers." Instituto di Matematica Computazionale, Pisa, Italy. April 1999. http://www.chez.com/powersum/Tr-b4-08.zip

Double Bubble: (2025-02-06) Sullivan, J. M. "Double Bubble Images." http://torus.math.uiuc.edu/jms/Images/double/

Egyptian Fraction: (1998-02-14) Gardner, M. "Babylonian and Egyptian Mathematics, an Egyptian Historical Gap, Installments 1-3." http://www.teleport.com/~ddonahue/phresour.html

Fibonacci Number: (2003-02-25) Leyland, P. ftp://sable.ox.ac.uk/pub/math/factors/fibonacci.Z

Flower of Life: (2003-02-25) Wein, J. "La Fleur de Vie." http://www2.cruzio.com/~flower/fleur.htm

Fullerene: (2026-05-04) Royle, G. "Fullerenes." http://school.maths.uwa.edu.au/~gordon/remote/fullerenes/

Game of Life: (1999-11-15) McIntosh, H. V. "Life." http://www.cs.cinvestav.mx/mcintosh/oldweb/life.html

Generalized Fermat Number: (2026-05-16) Broadhurst, D. "GFN Conjecture." Post to primeform user forum. Apr. 1, 2006. http://groups.yahoo.com/group/primeform/message/7187

Goblet Illusion: (1998-02-01) "Reversible Goblet." http://www.nari.ee.ethz.ch/nari_lectures/bildkom/Studenten_Projekte/Sommer96/Projekt5/sub1/goblet.html

Haberdasher's Problem: (1999-12-06) Chuan, J. C. "Geometric Construction." http://www.math.ntnu.edu.tw/gc/chuan/gc.html

Hexiamond: (2000-07-09) Paulhus, M. "The Hexiamond Home Page." http://www.math.ucalgary.ca/~paulhusm/hexiamond1/

Hyperbolic Plane: (2026-05-01) Taimina, D. "Mysteries of the Hyperbolic Plane." Carleton College News, May 18, 2006. http://apps.carleton.edu/news/?content=content&module=&id=193307

Illusion: (1998-02-01) "Illusions." http://www.nari.ee.ethz.ch/nari_lectures/bildkom/Studenten_Projekte/Sommer96/Projekt5/optic.html "Illusions: Central Station." https://web.archive.org/web/19970104154420/http://www.heureka.fi:80/i/Illusions_ctrl_station.html.en.

Knot: (1997-08-18) Zia. "Zia Knotting." http://204.30.30.10/hac/knots/

Lucas Number: (2026-05-16) Broadhurst, D. and Irvine, S. "Lucas Record." Post to primeform user forum. Jun. 19, 2006. http://groups.yahoo.com/group/primeform/message/7534

Lucas Number: (2003-02-25) Leyland, P. ftp://sable.ox.ac.uk/pub/math/factors/lucas.Z

Magic Circles: (1999-12-06) Hung, K. M. "Magic Circle." http://home.hkstar.com/~hkm88630/magiccl.html

Minimal Enclosing Circle: (2025-03-31) Elisoff, J. and Unger, R. "Minimal Enclosing Circle Problem." Oct. 1998. http://www.cs.mcgill.ca/~cs507/projects/1998/jacob/problem.html

Multiperfect Number: (1996-10-07) Perrier, J.-Y. "The Multi-Perfect Numbers." http://diwww.epfl.ch/~perrier/Multiparfaits.html

Narcissistic Number: (2000-07-09) Corning, T. "Exponential Digital Invariants." http://members.aol.com/tec153/Edi4web/Edi.html

Near-Square Prime: (2026-05-16) Minovic, P. "Carol/Kynea New Records." primenumbers discussion group. Feb. 20, 2004a. http://groups.yahoo.com/group/primenumbers/message/14574

Near-Square Prime: (2026-05-16) Minovic, P. "Re: Carol/Kynea New Records." primenumbers discussion group. Feb. 24, 2004b. http://groups.yahoo.com/group/primenumbers/message/14586

Noncayley Graph: (2026-05-04) Royle, G. "Transitive Graphs." http://school.maths.uwa.edu.au/~gordon/trans/

Nonhamiltonian Vertex-Transitive Graph: (2026-05-04) Royle, G. "Transitive Graphs." http://school.maths.uwa.edu.au/~gordon/trans/

Oloid: (2003-02-26) Capocasa, C. "Oloid." http://www.blackpoint.net/capocssa/oloid.html

Pi: (2003-02-25) Plouffe, S. "1 Billion Digits of Pi." http://pi.lacim.uqam.ca/eng/

Pi: (2025-12-19) Plouffe, S. "PiHex: A Distributed Effort to Calculate Pi." http://www.cecm.sfu.ca/projects/pihex/

Pi: (2025-12-15) Plouffe, S. "The Page." http://www.cecm.sfu.ca/pi/

Pi Digits: (2003-02-25) Kanada, Y. "Our Latest Record." Sep. 20, 1999. ftp://www.cc.u-tokyo.ac.jp/README.our_latest_record

Power Difference Prime: (2026-05-16) Andersen, J. K. "RE: Is There a Pattern?" 28 Nov 2005. http://groups.yahoo.com/group/primenumbers/message/17255

Power Difference Prime: (2026-05-16) Underwood, M. "RE: Is There a Pattern?" 28 Nov 2005. http://groups.yahoo.com/group/primenumbers/message/17254

Prime Arithmetic Progression: (2026-05-16) Andersen, J. K. "CC7 and AP9 Records." Post to primeform user forum. Apr. 6, 2006. http://groups.yahoo.com/group/primeform/message/7265/

Prime Arithmetic Progression: (2026-05-16) Davis, K. "New AP6 Record." primeform@yahoogroups.com mailing list. Apr. 28, 2006. http://groups.yahoo.com/group/primeform/message/7361

Prime Arithmetic Progression: (2026-05-16) Oakes, M. "New AP6 Record." Post to primeform user forum. Mar. 31, 2006. http://groups.yahoo.com/group/primeform/message/7164/

Prime Products: (2026-05-16) Oakes, M. "Re: [PrimeNumbers] pi=(2/1) (3/2) (5/6) (7/6) (11/10) (13/14) (17/18) (19/18)...." Dec. 21, 2003. http://groups.yahoo.com/group/primenumbers/message/14257

Prime Products: (2026-05-16) Oakes, M. "Re: primes and pi." Jan. 29, 2004. http://groups.yahoo.com/group/primenumbers/message/14486

Primorial Prime: (2003-02-25) Leyland, P. ftp://sable.ox.ac.uk/pub/math/factors/primorial-.Z

Quadric: (2003-02-25) Takahashi, H. "Quadrica Page." http://www2.kawase-h.ed.jp/Teachers/~Takahashi/Quadrica.html

Qubic: (2005-08-06) Allis, L. V. "Qubic." http://www.cs.vu.nl/~victor/qubic.html

RSA Number: (2026-05-16) Franke, J. "RSA576." Privately circulated email reposted to primenumbers Yahoo! Group. http://groups.yahoo.com/group/primenumbers/message/14113

RSA Number: (2003-02-25) Leyland, P. ftp://sable.ox.ac.uk/pub/math/rsa129

Self-Complementary Graph: (2026-05-04) Royle, G. "Self-Complementary Graphs." http://school.maths.uwa.edu.au/~gordon/remote/selfcomp/

Sexy Primes: (2026-05-16) Andersen, J. K. "Gigantic Sexy and Cousin Primes." Post to primeform user forum. Nov. 3, 2005. http://groups.yahoo.com/group/primeform/message/6637

Sexy Primes: (2026-05-16) Davis, K. "5132 Digit BLS Provable CPAP3 (diff=6)." Post to primeform user forum. Oct. 19, 2005. http://groups.yahoo.com/group/primeform/message/6542

Sierpiński Number of the Second Kind: (2026-05-16) Broadhurst, D. "Might Jean Complexify SoB?" primeform group posting. Oct. 30, 2005. http://groups.yahoo.com/group/primeform/message/6620/

Silverman Constant: (2026-05-18) Zimmermann, P. "Re: A Peculiar Sum." http://algo.inria.fr/csolve/zimmermn.html

Singular Integral: (2004-09-28) Paulino, G. H. "Singular Integrals." Fall 2001. http://cee.ce.uiuc.edu/paulino/BEM/handouts/sing.pdf

Sophie Germain Prime: (2026-05-16) Minovic, P. "RE: Record Sophie Germain Prime Pair." Jan 11, 2005. http://groups.yahoo.com/group/primenumbers/message/15873

Sophie Germain Prime: (2026-05-16) Underbakke, D. "Record Sophie Germain Prime Pair." Jan 11, 2005. http://groups.yahoo.com/group/primenumbers/message/15872

Sophie Germain Prime: (2026-05-16) Underwood, P. "Sophie Germain Record Primes." Message to primeform e-mail list. May 3, 2006. http://groups.yahoo.com/group/primeform/message/7378

Spikey: (2018-12-07) Bell, R. "Spiky: The Temple of Archimedes." http://www.zomadic.com/spiky/

Steinbach Screw: (2000-07-09) Naylor, B. "Steinbach Screw 1." http://www.garlic.com/~bnaylor/raytrace/rtstein1.html

Surface: (2003-02-25) Endraß, S. "Home Page of S. Endraß." http://www.mathematik.uni-mainz.de/~endrass/

Tautochrone Problem: (2003-02-25) Muterspaugh, J.; Driver, T.; and Dick, J. E. "The Cycloid and Tautochronism." http://php.indiana.edu/~jedick/project/intro.html

Tautochrone Problem: (2003-02-25) Muterspaugh, J.; Driver, T.; and Dick, J. E. "P221 Tautochrone Problem." http://php.indiana.edu/~jedick/project/project.html

Ternary Diagram: (2025-12-15) Vaughn, W. "Ternary Plots." 2010. http://wvaughan.org/ternaryplots.html

Vampire Number: (2008-12-25) Schneider, W. "Vampire Numbers." http://wschnei.de/digit-related-numbers/vampire.html Sloane, N. J. A. Sequences A014575, A048933, A048934, A048935, A048936, A048937, A048938, and A048939 in "The On-Line Encyclopedia of Integer Sequences."

Vertex-Transitive Graph: (2026-05-04) Royle, G. "Transitive Graphs." http://school.maths.uwa.edu.au/~gordon/trans/