Voozh

A063581

Smallest k such that 4^k has exactly n 6's in its decimal representation.

1, 2, 8, 18, 30, 50, 36, 64, 62, 104, 96, 133, 98, 115, 111, 110, 150, 193, 191, 242, 189, 288, 224, 253, 292, 308, 318, 254, 303, 331, 414, 389, 405, 373, 479, 436, 425, 504, 537, 499, 523, 543, 498, 600, 546, 584, 643, 640, 656, 626, 663

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

OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

MATHEMATICA

a = {}; Do[k = 1; While[ Count[ IntegerDigits[4^k], 6] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a

Log[4, #]&/@Table[First[Select[4^Range[900], DigitCount[#, 10, 6]==n&]], {n, 0, 60}] (* Harvey P. Dale, May 15 2011 *)

CROSSREFS

Sequence in context: A065131 A192157 A268810 * A293296 A055044 A356209

Adjacent sequences: A063578 A063579 A063580 * A063582 A063583 A063584

KEYWORD

base,nonn

AUTHOR

Robert G. Wilson v, Aug 10 2001

EXTENSIONS

Name corrected by Jon E. Schoenfield, Jun 26 2018

STATUS

approved

URL: https://oeis.org/A063581

⇱ A063581 - OEIS