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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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified December 1 16:44 EST 2021. Contains 349430 sequences. (Running on oeis4.)