

A288291


Position of the first time an ndigit number appears twice in a row after the decimal point of e.


2




OFFSET

1,1


COMMENTS

18281828 appears in e before any 1digit, 2digit, or 3digit number appears twice in a row.


LINKS

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


EXAMPLE

a(1) = 31 because the first time a 1digit number appears twice in a row in the decimal expansion of e is 31 digits after the decimal point: 2.718281828459045235360287471352(66)...


MATHEMATICA

s = First@ RealDigits[E, 10, 51*^5]; Table[p = Partition[s, k, 1];
SelectFirst[ Range[ Length[p]  k], p[[#]] == p[[# + k]] &]  1, {k, 7}] (* Giovanni Resta, Sep 05 2017 *)


CROSSREFS

Cf. A001113, A287994, A290984.
Sequence in context: A244601 A004224 A194129 * A248904 A068779 A068473
Adjacent sequences: A288288 A288289 A288290 * A288292 A288293 A288294


KEYWORD

nonn,base,more


AUTHOR

Bobby Jacobs, Sep 01 2017


EXTENSIONS

a(6)a(8) from Giovanni Resta, Sep 05 2017


STATUS

approved



