A217190 a(n) is the number of digits in the decimal representation of the smallest power of 11 that contains n consecutive identical digits.

1, 2, 9, 41, 163, 502, 1378, 3107, 9834, 41530, 223636, 308352, 308352

Offset: 1

Author

V. Raman, Sep 27 2012

Keywords

• nonn
• base

Comments

Number of digits in 11^k is equal to floor(1 + k*log_10(11)).

Crossrefs

Cf. A215731, A215737.

Programs

Mathematica

k = 0; Join[{1}, Table[While[d = IntegerDigits[11^k]; prt = Partition[Differences[d], n - 1, 1]; ! MemberQ[prt, Table[0, {n - 1}]], k++]; Length[d], {n, 2, 8}]] (* T. D. Noe, Oct 03 2012 *)

Extensions

a(10)-a(13) added by V. Raman, Apr 30 2012, in correspondence with A215731.