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A166028 a(n) is the starting position of the second occurrence of a string of the initial n decimal digits of e in the decimal expansion of e. 1
4, 62, 918, 5503, 29169, 252474, 7910575, 7910575 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The digits 2 7 1 8 2 ... are labeled 0, 1, 2, 3, 4, ...

The next term, a(9), is greater than 50 million. - Harvey P. Dale, Apr 01 2017

LINKS

Table of n, a(n) for n=1..8.

EXAMPLE

a(6) is the starting position of the second occurrence of the initial 6 decimals of e. the string '271828' occurs at position 252,474, thus a(6) = 252,474.

MATHEMATICA

Module[{nn=300000, ed}, ed=RealDigits[E, 10, nn][[1]]; Table[ SequencePosition[ ed, Take[ed, n], 2][[2]], {n, 6}][[All, 1]]-1] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Apr 01 2017 *)

CROSSREFS

Cf. A001113, A081876

Sequence in context: A316391 A293968 A222791 * A241997 A332694 A277392

Adjacent sequences:  A166025 A166026 A166027 * A166029 A166030 A166031

KEYWORD

base,nonn

AUTHOR

Steven Lubars (lubars(AT)gmail.com), Oct 04 2009

EXTENSIONS

Two more terms -- a(7) and a(8) -- from Harvey P. Dale, Apr 01 2017

STATUS

approved

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Last modified December 2 17:39 EST 2021. Contains 349445 sequences. (Running on oeis4.)