

A063570


Smallest positive power of 7 having n in its decimal representation.


2



4, 4, 4, 3, 2, 7, 5, 1, 5, 2, 13, 6, 12, 12, 19, 15, 5, 6, 19, 11, 12, 22, 14, 7, 4, 30, 11, 23, 10, 16, 14, 19, 11, 16, 3, 7, 9, 19, 12, 17, 4, 12, 27, 3, 18, 21, 32, 10, 8, 2, 15, 17, 10, 9, 7, 21, 15, 8, 21, 18, 9
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OFFSET

0,1


LINKS

Chai Wah Wu, Table of n, a(n) for n = 0..10000


MATHEMATICA

a = {}; Do[k = 1; While[ StringPosition[ ToString[7^k], ToString[n] ] == {}, k++ ]; a = Append[a, k], {n, 0, 60} ]; a


PROG

(Python)
def A063570(n):
m, k, s = 1, 7, str(n)
while s not in str(k):
m += 1
k *= 7
return m # Chai Wah Wu, Nov 14 2019


CROSSREFS

Essentially the same as A062524.
Sequence in context: A063448 A232526 A117499 * A023977 A073259 A174987
Adjacent sequences: A063567 A063568 A063569 * A063571 A063572 A063573


KEYWORD

base,nonn


AUTHOR

Robert G. Wilson v, Aug 10 2001


STATUS

approved



