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Champernowne Constant Digits


The decimal digits of the Champernowne constant C begin

 C=0.1234567891011...

(OEIS A033307).

The Earls sequence (starting position of n consecutive copies of the decimal representation of the positive integer n) for C is given for n=1, 2, ... by 1, 34, 56, 1222, 1555, 25554, 29998, 433330, 7988888882, 1101010101010, ... (OEIS A224896).

The starting positions of the first occurrence of the decimal representation of n=0, 1, 2, ... in the decimal expansion of C (not including the initial 0 to the left of the decimal point) are 11, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 1, ... (OEIS A229186).

Scanning the fractional decimal expansion of C until all strings of n decimal digits, including those with leading zeros, have occurred, the last strings of 1, 2, ... decimal digits appearing are 0, 00, 000, 0000, ..., which end at decimal digits 11, 192, 2893, 38894, 488895, ... (OEIS A072290).

The first few starting positions of the sequence of decimal digits 0123456789 are 11234567799, 22345677908, 33456779017, 44567790126, 55677901235, 66779012344, ... and those of 9876543210 are 7777777779, 9876543212, 19987654323, 30998765434, 42099876545, 53209987656, 64320998767, ... (E. Weisstein, Jul. 26, 2013).

Reported C-constant primes or probable primes have 10, 14, 24, 235, 2804, 4347, 37735, ... (OEIS A071620) decimal digits.

It is known that the Champernowne constant is normal in base 10 (Champernowne 1933, Bailey and Crandall 2002), though the following table giving the counts of decimal digits in the first 10^n fractional decimal digits shows unequal finite frequencies through 10^9 decimal digits, with an excess of 1s and a deficit of 0s when cutting the decimal-digit string off at locations such as ...123456787123456788.

d\10^nOEIS1010010^310^410^510^610^710^810^9
00566747864283528884151923456896021948
1216177185819753179810158256214234568130589850
21161771636111119453999526010345679100589849
31161488588642945399951611023456896589849
411677858864294539995160934567996089849
511177858864293723982462934567996029849
61577858864293538895160934567996022849
71567833864293538894462934567996022049
81567747864288718891462933333396021959
91567747864283528884160923456896021949

See also

Champernowne Constant, Champernowne Constant Continued Fraction, Constant Digit Scanning, Constant Primes, Earls Sequence, Smarandache Number

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References

Bailey, D. H. and Crandall, R. E. "Random Generators and Normal Numbers." Exper. Math. 11, 527-546, 2002.Champernowne, D. G. "The Construction of Decimals Normal in the Scale of Ten." J. London Math. Soc. 8, 254-260, 1933. https://doi.org/10.1112/jlms/s1-8.4.254.Sloane, N. J. A. Sequences A033307, A071620, A072290, A224896, and A229186 in "The On-Line Encyclopedia of Integer Sequences."

Referenced on Wolfram|Alpha

Champernowne Constant Digits

Cite this as:

Weisstein, Eric W. "Champernowne Constant Digits." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/ChampernowneConstantDigits.html

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