login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A063576 Smallest k such that 4^k has exactly n 1's in its decimal representation. 2
1, 2, 12, 17, 29, 40, 35, 57, 112, 61, 108, 109, 101, 84, 167, 188, 182, 186, 205, 259, 252, 240, 269, 320, 329, 283, 305, 317, 300, 400, 288, 413, 458, 360, 392, 466, 447, 477, 383, 493, 481, 574, 598, 497, 567, 551, 599, 603, 676, 721, 564 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Robert Israel, Table of n, a(n) for n = 0..2000

MAPLE

N:= 100: # for a(0)..a(N)

A:= Array(0..N):

count:= 0:

for k from 1 while count < N+1 do

  v:= numboccur(1, convert(4^k, base, 10));

  if v <= N and A[v] = 0 then A[v]:= k; count:= count+1; fi

od:

convert(A, list); # Robert Israel, Jul 03 2020

MATHEMATICA

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

With[{p4=Table[DigitCount[4^n, 10, 1], {n, 750}]}, Table[Position[p4, i, 1, 1], {i, 0, 50}]]//Flatten (* Harvey P. Dale, May 05 2018 *)

CROSSREFS

Cf. A000302 (powers of 4).

Sequence in context: A057827 A266802 A082407 * A144264 A277961 A294998

Adjacent sequences:  A063573 A063574 A063575 * A063577 A063578 A063579

KEYWORD

base,nonn,changed

AUTHOR

Robert G. Wilson v, Aug 10 2001

EXTENSIONS

Name corrected by Jon E. Schoenfield, Jun 26 2018

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 12 06:21 EDT 2020. Contains 335658 sequences. (Running on oeis4.)