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Constant Digit Scanning


Constant digit scanning consists of scanning the decimal expansion of a positive constant until all n-digit strings have been seen, where n is a positive integer. The strings may overlap and include leading zeros. The decimal point and an initial 0 to its left are omitted.

The following table gives the number of digits that must be scanned to encounter all n=1, 2, ...-digit strings, together with the last n-digit string encountered. The scan count is the ending position of that string. For each constant, the first row lists scan counts and the second row, when present, lists last strings. Last strings are read as having n digits, adding leading zeros when necessary.

constantOEISsequence
Apéry's constantA03690623, 457, 7839, 83054, 1256587, 13881136, 166670757, ...
A0369027, 89, 211, 2861, 43983, 292702, 8261623, ...
Catalan's constant32, 716, 7700, 86482, 1143572, ...
8, 45, 529, 2679, 24200, ...
Champernowne constantA07229011, 192, 2893, 38894, 488895, 5888896, 68888897, 788888898, 8888888899, ...
Copeland-Erdős constant48, 934, 24437, 366399, 4910479, 49672582, ...
0, 84, 504, 8580, 07010, 088880, ...
eA03690421, 372, 8092, 102128, 1061613, 12108841, 198150341, 1929504534, ...
A0369006, 12, 548, 1769, 92994, 513311, 1934715, 56891305, ...
Euler-Mascheroni constant16, 658, 6600, 91101, 1384372, ...
8, 18, 346, 2778, 84514, ...
Glaisher-Kinkelin constant22, 495, 8268, ...
5, 98, 478, ...
golden ratio23, 770, 5819, 93910, 1154766, 13192647, ...
5, 55, 515, 0092, 67799, 290503, ...
Golomb-Dickman constant28, 587, 6322, ...
1, 33, 821, ...
Khinchin's constant23, 499, 8254, ...
7, 43, 782, ...
natural logarithm of 2A03690522, 444, 7655, 98370, 1107795, 12983306, ...
A0369012, 98, 604, 1155, 46847, 175403, ...
natural logarithm of 10A22912422, 701, 7486, 88092, 1189434, 13426407, ...
A2291267, 38, 351, 8493, 33058, 362945, ...
piA08059733, 607, 8556, 99850, 1369565, 14118313, 166100507, 1816743913, 22445207407, 241641121049, 2512258603208, ...
A0325100, 68, 483, 6716, 33394, 569540, 1075656, 36432643, 172484538, 5918289042, 56377726040, ...
Pythagoras's constant19, 420, 8326, 94388, 1256460, 13043524, ...
8, 81, 748, 8505, 30103, 489568, ...
Soldner's constant34, 512, 7454, 92508, ...
7, 46, 102, 5858, ...
Theodorus's constant23, 378, 7862, 77437, 1237533, 16362668, ...
4, 91, 184, 5566, 86134, 35343, ...

The starting positions of the first occurrence of the unpadded decimal representations of n=0, 1, 2, ... in the decimal expansion of a number of constants are summarized in the table below.

constantOEISfirst occurrence of 0, 1, 2, ...
Apéry's constantA2291873, 1, 2, 10, 16, 6, 7, 23, 18, 8, ...
Catalan's constantA10007916, 2, 13, 24, 9, 3, 5, 11, 32, 1, ...
Champernowne constantA22918611, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ...
Copeland-Erdős constantA22919048, 5, 1, 2, 21, 3, 31, 4, 41, 12, ...
eA08857614, 3, 1, 18, 11, 12, 21, 2, 4, 13, ...
Euler-Mascheroni constantA22919211, 5, 4, 14, 9, 1, 7, 2, 16, 10, 36, ...
Glaisher-Kinkelin constantA22919312, 1, 2, 18, 5, 22, 14, 7, 3, 10, 11, ...
Golomb-Dickman constantA22919515, 28, 2, 4, 3, 10, 1, 17, 8, 6, 28, ...
golden ratioA0885775, 1, 20, 6, 12, 23, 2, 11, 4, 8, 232, ...
Khinchin's constantA2291968, 10, 1, 14, 5, 4, 2, 23, 3, 22, 10, ...
natural logarithm of 2A1000779, 4, 22, 3, 5, 10, 1, 6, 8, 2, 108, ...
natural logarithm of 10A2291973, 21, 1, 2, 13, 5, 17, 22, 6, 9, 41, ...
piA03244533, 2, 7, 1, 3, 5, 8, 14, 12, 6, 50, ...
Pythagoras's constantA22919914, 1, 5, 7, 2, 8, 9, 12, 19, 15, 77, ...
Soldner's constantA22920117, 1, 8, 5, 2, 3, 6, 34, 11, 7, 16, ...
Theodorus's constantA2292005, 1, 4, 3, 23, 6, 12, 2, 8, 18, 48, ...

See also

Constant, Constant Primes

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References

Sloane, N. J. A. Sequences A032445, A032510, A036900, A036901, A036902, A036904, A036905, A036906, A072290, A080597, A088576, A088577, A100077, A100079, A229124, A229126, A229186, A229187, A229190, A229192, A229193, A229195, A229196, A229197, A229199, A229200, and A229201 in "The On-Line Encyclopedia of Integer Sequences."

Referenced on Wolfram|Alpha

Constant Digit Scanning

Cite this as:

Weisstein, Eric W. "Constant Digit Scanning." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/ConstantDigitScanning.html

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