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A217163 a(n) is the least value of k such that the decimal expansion of n^k contains eight or more consecutive identical digits. 3
8554, 7720, 4277, 2790, 8533, 6176, 4442, 3860, 8, 2983, 2430, 5482, 1053, 5030, 3502, 5781, 3982, 4706, 8, 2568, 4850, 2740, 4549, 1395, 699, 2960, 2679, 3197, 8, 4057, 2709, 3115, 3436, 1190, 6629, 692, 3274, 5773, 8, 6997, 3536, 5936, 647, 3204, 1369, 1587 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

LINKS

V. Raman, Table of n, a(n) for n = 2..100

MATHEMATICA

Table[k = 1; While[! MemberQ[Partition[Differences[IntegerDigits[n^k]], 7, 1], {0, 0, 0, 0, 0, 0, 0}], k++]; k, {n, 2, 50}] (* T. D. Noe, Oct 01 2012 *)

lvk8[n_]:=Module[{k=Ceiling[Log[n, 11111111]]}, While[Max[Length/@ Split[ IntegerDigits[n^k]]]<8, k++]; k] Array[lvk8, 50, 2] (* Harvey P. Dale, Jul 31 2013 *)

CROSSREFS

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

Sequence in context: A202986 A297896 A217338 * A243839 A287119 A156846

Adjacent sequences:  A217160 A217161 A217162 * A217164 A217165 A217166

KEYWORD

nonn,base

AUTHOR

V. Raman, Sep 27 2012

EXTENSIONS

Definition clarified by Harvey P. Dale, Jul 31 2013

STATUS

approved

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Last modified September 24 15:58 EDT 2022. Contains 356943 sequences. (Running on oeis4.)