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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
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
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
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