A063556 Smallest k such that 3^k has exactly n 1's in its decimal representation.

1, 4, 11, 17, 32, 42, 85, 55, 84, 100, 115, 120, 162, 128, 202, 111, 214, 267, 260, 316, 321, 319, 295, 307, 298, 331, 384, 404, 451, 454, 490, 488, 449, 521, 528, 511, 575, 617, 584, 604, 590, 628, 663, 619, 668, 807, 776, 812, 718, 788, 856, 796, 956, 960

Offset

0,2

Links

Robert Israel, Table of n, a(n) for n = 0..1000

Maple

f:= proc(n) numboccur(1, convert(3^n, base, 10)) end proc:
N:= 100: # for a(0) .. a(N)
V:= Array(0..N): count:= 0:
for k from 1 while count <= N do
  v:= f(k);
  if v <= N and V[v] = 0 then V[v]:= k; count:= count+1; fi
od:
convert(V, list); # Robert Israel, Sep 07 2023

Mathematica

a = {}; Do[k = 1; While[ Count[ IntegerDigits[3^k], 1] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a

Crossrefs

Sequence in context: A003146 A063237 A026381 * A133725 A050395 A368424

Adjacent sequences: A063553 A063554 A063555 * A063557 A063558 A063559

Keyword

base,nonn

Author

Robert G. Wilson v, Aug 10 2001

Extensions

Name corrected by Jon E. Schoenfield, Jun 26 2018

Status

approved