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A063557 Smallest k such that 3^k has exactly n 2's in its decimal representation. 0
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified October 14 17:43 EDT 2019. Contains 328022 sequences. (Running on oeis4.)