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Search: id:A023103
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| A023103 |
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(10^n)-th digit of infinite string 12345678910111213141516... |
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+0
2
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| 1, 1, 5, 3, 7, 2, 1, 7, 8, 1, 1, 0, 1, 5, 7, 2, 6, 4, 3, 5, 3, 5, 4, 9, 6, 2, 4, 8, 7, 1, 1, 3, 7, 2, 3, 0, 8, 5, 3, 8, 2, 7, 6, 7, 9, 9, 2, 7, 0, 1, 6, 2, 0, 4, 1, 3, 8, 5, 3, 3, 3, 5, 0, 0, 1, 1, 5, 6, 1, 6, 2, 4, 3, 7, 5, 6, 8, 5, 3, 6, 8, 8, 2, 2, 0, 3, 9, 1, 8, 9, 2, 1, 1, 9, 6, 4, 4, 0, 2, 6, 4, 1, 0, 1, 4, 2, 8, 4
(list; graph; listen)
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OFFSET
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0,3
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COMMENT
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In one of Ross Honsberger's "Mathematical Gems" series (Dolciani Mathematical Expositions, Mathematical Association of America) there is a formula for extracting the n-th digit. Would someone submit it?
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REFERENCES
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M. Kraitchik, Mathematical Recreations. Dover, NY, 2nd ed., 1953, p. 49.
Unknown, Algorithms & Their Computer Solutions, p 160.
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MATHEMATICA
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f[n_] := Block[{m = 0, d = n, i = 1, l, p}, While[m <= d, l = m; m = 9i*10^(i - 1) + l; i++ ]; i--; p = Mod[d - l, i]; q = Floor[(d - l)/i] + 10^(i - 1); If[p != 0, IntegerDigits[q][[p]], Mod[q - 1, 10]]];
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CROSSREFS
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10^n-th digit in the almost natural number (A007376).
Cf. Champernowne constant or Mahler's number A033307.
Cf. A033713.
Sequence in context: A066253 A065169 A099217 this_sequence A117126 A048997 A096635
Adjacent sequences: A023100 A023101 A023102 this_sequence A023104 A023105 A023106
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KEYWORD
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nonn,base
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AUTHOR
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David W. Wilson (davidwwilson(AT)comcast.net)
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EXTENSIONS
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Edited by Robert G. Wilson v (rgwv(AT)rgwv.com), Jun 18 2002
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