A217178 a(n) is the number of digits in the decimal representation of the smallest power of n that contains three consecutive identical digits.
8, 16, 8, 35, 4, 27, 8, 16, 4, 9, 19, 28, 17, 28, 8, 15, 8, 12, 4, 15, 10, 21, 20, 35, 16, 16, 15, 8, 5, 11, 13, 16, 16, 28, 15, 24, 4, 20, 5, 23, 7, 12, 20, 30, 20, 14, 29, 29, 6, 26, 18, 13, 20, 44, 42, 15, 20, 18, 6, 25, 20, 33, 8, 13, 17, 24, 13, 23, 6, 21
Offset: 2
Links
- V. Raman, Table of n, a(n) for n = 2..10000
Programs
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Mathematica
Table[k = 1; While[d = IntegerDigits[n^k]; ! MemberQ[Partition[Differences[d], 2, 1], {0, 0}], k++]; Length[d], {n, 2, 100}] (* T. D. Noe, Oct 03 2012 *) spn3[n_]:=Module[{p=1},While[SequenceCount[IntegerDigits[n^p],{x_,x_,x_}]<1,p++];IntegerLength[n^p]]; Array[spn3,80,2] (* Harvey P. Dale, Nov 10 2022 *)
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