A217160 a(n) is the least value of k such that the decimal expansion of n^k contains five consecutive identical digits.

220, 274, 110, 125, 226, 172, 105, 137, 5, 156, 40, 227, 196, 216, 55, 235, 78, 115, 5, 104, 133, 187, 126, 93, 115, 110, 21, 163, 5, 40, 44, 159, 104, 110, 113, 20, 200, 205, 5, 119, 142, 116, 90, 145, 156, 136, 37, 86, 5, 37, 62, 119, 85, 91, 107, 142, 40

Offset

2,1

Links

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

Mathematica

Table[k = 1; While[! MemberQ[Partition[Differences[IntegerDigits[n^k]], 4, 1], {0, 0, 0, 0}], k++]; k, {n, 2, 100}] (* T. D. Noe, Oct 01 2012 *)

Crossrefs

Cf. A045875, A215727, A215728, A215729, A215730, A215731.

Sequence in context: A064477 A371808 A371806 * A203777 A274116 A121507

Adjacent sequences: A217157 A217158 A217159 * A217161 A217162 A217163

Keyword

nonn,base

Author

V. Raman, Sep 27 2012

Status

approved