

A217187


a(n) is the number of digits in the decimal representation of the smallest power of 5 that contains n consecutive identical digits.


0



1, 8, 35, 67, 88, 760, 1948, 1951, 1955, 1956, 1959, 1960
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OFFSET

1,2


COMMENTS

Number of digits in 5^k is equal to floor(1 + k*log_10(5)).


LINKS

Table of n, a(n) for n=1..12.


MATHEMATICA

k = 0; Join[{1}, Table[While[d = IntegerDigits[5^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 *)


CROSSREFS

Cf. A215728, A215734.
Sequence in context: A317263 A275360 A281147 * A214725 A136016 A257454
Adjacent sequences: A217184 A217185 A217186 * A217188 A217189 A217190


KEYWORD

nonn,base


AUTHOR

V. Raman, Sep 27 2012


STATUS

approved



