login
a(n) is the least value of k such that the decimal expansion of n^k contains nine consecutive identical digits.
3

%I #11 Oct 01 2012 14:28:21

%S 42485,22791,21243,2796,27717,33836,14162,22076,9,9443,11429,16661,

%T 16548,11259,10622,14991,5786,28096,9,2890,16736,14116,4549,1398,

%U 27735,7597,3614,10332,9,4057,8497,9060,23985,2943,13859,11422,13270,5773,9,14777,11541

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

%H V. Raman, <a href="/A217164/b217164.txt">Table of n, a(n) for n = 2..100</a>

%t Table[k = 1; While[! MemberQ[Partition[Differences[IntegerDigits[n^k]], 8, 1], {0, 0, 0, 0, 0, 0, 0, 0}], k++]; k, {n, 2, 50}] (* _T. D. Noe_, Oct 01 2012 *)

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

%K nonn,base

%O 2,1

%A _V. Raman_, Sep 27 2012