A063570 Smallest positive power of 7 having n in its decimal representation.

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

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: A232526 A358328 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