A063630 Smallest k such that 9^k has exactly n 4's in its decimal representation.

1, 5, 6, 10, 30, 29, 43, 45, 36, 73, 75, 92, 68, 116, 102, 85, 98, 141, 166, 151, 109, 154, 172, 196, 175, 176, 217, 244, 245, 207, 275, 226, 242, 289, 269, 263, 297, 261, 326, 296, 355, 335, 369, 336, 412, 414, 360, 458, 394, 457, 404

Offset

0,2

Links

Table of n, a(n) for n=0..50.

Mathematica

a = {}; Do[k = 1; While[ Count[ IntegerDigits[9^k], 4] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a
With[{ns=9^Range[500]}, Log[9, #]&/@Flatten[Table[Select[ns, Count[ IntegerDigits[#], 4]==n&, 1], {n, 0, 50}]]] (* Harvey P. Dale, Oct 20 2011 *)

Crossrefs

Sequence in context: A018834 A029943 A356760 * A342127 A119102 A162015

Adjacent sequences: A063627 A063628 A063629 * A063631 A063632 A063633

Keyword

base,nonn

Author

Robert G. Wilson v, Aug 10 2001

Extensions

Name corrected by Jon E. Schoenfield, Jun 26 2018

Status

approved