A217168 a(n) is the first digit (from the left) to appear three times in succession in the decimal representation of n^A217158(n).

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

Offset: 2

Author

V. Raman, Sep 27 2012

Keywords

• nonn
• base

Links

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

Crossrefs

Cf. A217158.

Cf. A215732, A215733, A215734, A215735, A215736, A215737.

Programs

Mathematica

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