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A063578 Smallest k such that 4^k has exactly n 3's in its decimal representation. 1
1, 7, 26, 43, 38, 57, 48, 64, 81, 92, 91, 78, 104, 151, 155, 143, 162, 150, 173, 249, 267, 251, 339, 282, 333, 325, 275, 378, 345, 428, 415, 429, 473, 463, 411, 430, 513, 420, 507, 546, 508, 489, 533, 603, 566, 593, 641, 545, 707, 638, 722 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

MAPLE

N:= 100: # to get a(0) to a(N)

A:= Array(0..N):

count:= 0:

for n from 1 while count < N+1 do

   v:= numboccur(3, convert(4^n, base, 10));

   if v <= N and A[v] = 0 then

     count:= count+1;

     A[v]:= n;

   fi

od:

seq(A[i], i=0..N); # Robert Israel, Feb 24 2016

MATHEMATICA

a = {}; Do[k = 1; While[ Count[ IntegerDigits[4^k], 3] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a

CROSSREFS

Cf. A063576, A063577, A063579, A063580, A063581, A063582, A063583, A063584.

Sequence in context: A103267 A125972 A063153 * A063159 A274268 A059376

Adjacent sequences:  A063575 A063576 A063577 * A063579 A063580 A063581

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 July 16 09:13 EDT 2020. Contains 335784 sequences. (Running on oeis4.)