A217167 a(n) is the first digit (from the left) to appear two times in succession in the decimal representation of n^A217157(n).

5, 7, 5, 8, 7, 1, 4, 4, 0, 1, 4, 4, 4, 2, 5, 3, 8, 9, 0, 4, 2, 8, 3, 4, 1, 4, 7, 1, 0, 8, 3, 3, 1, 2, 6, 7, 4, 4, 0, 1, 8, 8, 4, 1, 1, 2, 1, 1, 0, 7, 1, 8, 1, 5, 4, 5, 3, 1, 0, 2, 4, 0, 4, 2, 6, 4, 4, 2, 0, 1, 0, 3, 2, 7, 7, 7, 5, 0, 0, 4, 5, 8, 1, 2, 0, 3, 8

Offset

2,1

Comments

Note that 109^2 = 11881. So by looking at the digits from the left, we have a(109) = 1.

Links

V. Raman, Table of n, a(n) for n = 2..10000

Mathematica

Table[k = 1; While[d = IntegerDigits[n^k]; ! MemberQ[df = Differences[d], 0], k++]; d[[Position[df, 0][[1, 1]]]], {n, 2, 100}] (* T. D. Noe, Oct 02 2012 *)

Crossrefs

Cf. A217157.

Cf. A215732, A215236.

Cf. A215733, A215734, A215735, A215736, A215737.

Sequence in context: A306400 A090987 A278813 * A348052 A195498 A065746

Adjacent sequences: A217164 A217165 A217166 * A217168 A217169 A217170

Keyword

nonn,base

Author

V. Raman, Sep 27 2012

Status

approved