

A023103


(10^n)th digit of infinite string 12345678910111213141516...


3



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
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OFFSET

0,3


COMMENTS

In one of Ross Honsberger's "Mathematical Gems" series (Dolciani Mathematical Expositions, Mathematical Association of America) there is a formula for extracting the nth digit. Would someone submit it? [Robert Wilson notes that the Mathematica program below implements this formula.]


REFERENCES

Lucio Artiaga and Lloyd D. Davis, Algorithms and Their Computer Solutions, Merrill, 1972, p. 160.
M. Kraitchik, Mathematical Recreations. Dover, NY, 2nd ed., 1953, p. 49.


LINKS

Robert G. Wilson v, Table of n, a(n) for n = 0..1000
Sean A. Irvine, Java program (github)


MATHEMATICA

almostNatural[n_, b_] := Block[{m = 0, d = n, i = 1, l, p}, While[m <= d, l = m; m = (b  1) i*b^(i  1) + l; i++]; i; p = Mod[d  l, i]; q = Floor[(d  l)/i] + b^(i  1); If[p != 0, IntegerDigits[q, b][[p]], Mod[q  1, b]]]; Array[ almostNatural[10^#, 10] &, 105, 0] (* modified by Robert G. Wilson v, Jul 15 2014 *)


CROSSREFS

10^nth digit in the almost natural number (A007376).
Cf. Champernowne constant or Mahler's number A033307.
Cf. A033713.
Sequence in context: A065169 A247617 A099217 * A153454 A198877 A201752
Adjacent sequences: A023100 A023101 A023102 * A023104 A023105 A023106


KEYWORD

nonn,base


AUTHOR

David W. Wilson


EXTENSIONS

Edited by Robert G. Wilson v, Jun 18 2002


STATUS

approved



