A063571 Smallest power of 8 having n in its decimal representation.

4, 3, 3, 5, 2, 3, 2, 5, 1, 4, 10, 14, 3, 9, 6, 7, 8, 9, 10, 12, 7, 6, 17, 21, 10, 17, 6, 5, 9, 20, 26, 25, 5, 21, 9, 15, 12, 10, 13, 14, 4, 10, 9, 14, 6, 11, 14, 12, 17, 13, 18, 3, 7, 29, 13, 13, 16, 25, 11, 11, 20

Offset

0,1

Comments

Variant of A062525 allowing only exponents larger than zero. [From R. J. Mathar, Dec 15 2008]

Links

Harvey P. Dale, Table of n, a(n) for n = 0..1000

Mathematica

a = {}; Do[k = 1; While[ StringPosition[ ToString[8^k], ToString[n] ] == {}, k++ ]; a = Append[a, k], {n, 0, 60} ]; a
sp8[n_]:=Module[{k=1}, While[SequenceCount[IntegerDigits[ 8^k], IntegerDigits[ n]]<1, k++]; k]; Array[sp8, 70, 0] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Apr 07 2017 *)

Prog

(Python)
def a(n):
  k, pow8, s = 1, 8, str(n)
  while s not in str(pow8): k += 1; pow8 *= 8
  return k
print([a(n) for n in range(61)]) # Michael S. Branicky, Apr 03 2021

Crossrefs

Sequence in context: A222616 A011762 A195780 * A005589 A362123 A052360

Adjacent sequences: A063568 A063569 A063570 * A063572 A063573 A063574

Keyword

base,nonn

Author

Robert G. Wilson v, Aug 10 2001

Status

approved