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Multimagic Series


A set n distinct numbers taken from the interval [1,n^2] form a magic series if their sum is the nth magic constant

 M_n=1/2n(n^2+1)

(Kraitchik 1942, p. 143). If the sum of the kth powers of these numbers is the magic constant of degree k for all k in [1,p], then they are said to form a pth order multimagic series. Here, the magic constant M_n^((j)) of degree k is defined as 1/n times the sum of the first n^2 kth powers,

 M_n^((k))=1/nsum_(i=1)^(n^2)i^k=(H_(n^2)^((-k)))/n,

where H_n^((k)) is a generalized harmonic number of order k.

For example {2,8,9,15} is bimagic since 2+8+9+15=34 and 2^2+8^2+9^2+15^2=374. It is also trimagic since 2^3+8^3+9^3+15^3=4624. Similarly, {3,5,12,14} is trimagic.

The numbers of magic series of various lengths n are gives in the following table for small orders k (Kraitchik 1942, p. 76; Boyer), where the k=2, 3, and 4 values were corrected and extended by Boyer and Trump in 2002.

nk=1k=2k=3k=4
SloaneA052456A052457A052458A090037
11111
22000
38000
486220
51394820
6321349800
7957332184400
835154340380391210
915374082029497381260
10781325415282464323600
114528684996756947689757311870
122950111860062822226896106

See also

Magic Series

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References

Boyer, C. "Multimagic Series." http://www.multimagie.com/English/Series.htm.Kraitchik, M. "Multimagic Squares." §7.10 in Mathematical Recreations. New York: W. W. Norton, pp. 176-178, 1942.Sloane, N. J. A. Sequences A052456, A052457, A052458, and A090037 in "The On-Line Encyclopedia of Integer Sequences."

Referenced on Wolfram|Alpha

Multimagic Series

Cite this as:

Weisstein, Eric W. "Multimagic Series." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/MultimagicSeries.html

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