A063557 Smallest k such that 3^k has exactly n 2's in its decimal representation.

1, 3, 19, 24, 56, 49, 60, 78, 87, 100, 108, 143, 169, 145, 210, 160, 183, 193, 260, 270, 312, 321, 325, 353, 348, 419, 388, 409, 316, 403, 465, 502, 483, 489, 561, 533, 443, 565, 691, 646, 677, 552, 721, 711, 687, 700, 791, 813, 768, 867, 806

Offset

0,2

Links

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

Mathematica

a = {}; Do[k = 1; While[ Count[ IntegerDigits[3^k], 2] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a
With[{pwr3=3^Range[1000]}, IntegerExponent[#, 3]&/@Flatten[Table[ Select[ pwr3, DigitCount[#, 10, 2]==n&, 1], {n, 0, 50}]]] (* Harvey P. Dale, Sep 09 2012 *)

Crossrefs

Sequence in context: A019408 A070045 A323784 * A197541 A273367 A295322

Adjacent sequences: A063554 A063555 A063556 * A063558 A063559 A063560

Keyword

base,nonn

Author

Robert G. Wilson v, Aug 10 2001

Extensions

Name corrected by Jon E. Schoenfield, Jun 26 2018

Status

approved