A217161 - OEIS

A217161

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

971, 538, 486, 1087, 371, 175, 324, 269, 6, 482, 362, 327, 196, 516, 243, 350, 288, 144, 6, 895, 822, 238, 481, 1137, 281, 180, 127, 358, 6, 286, 454, 286, 347, 110, 481, 346, 314, 448, 6, 565, 388, 275, 90, 622, 231, 451, 37, 255, 6, 481, 202, 191, 472, 308

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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]], 5, 1], {0, 0, 0, 0, 0}], k++]; k, {n, 2, 100}] (* T. D. Noe, Oct 01 2012 *)

lk[n_]:=Module[{k=1, t=Table[x_, 6]}, While[SequenceCount[IntegerDigits[ n^k], t]<1, k++]; k]; Array[lk, 60, 2] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 18 2018 *)

CROSSREFS

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

Sequence in context: A345538 A345790 A257975 * A243861 A171771 A206089

Adjacent sequences: A217158 A217159 A217160 * A217162 A217163 A217164

KEYWORD

nonn,base

AUTHOR

V. Raman, Sep 27 2012

STATUS

approved