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!)
A063581 Smallest k such that 4^k has exactly n 6's in its decimal representation. 2
1, 2, 8, 18, 30, 50, 36, 64, 62, 104, 96, 133, 98, 115, 111, 110, 150, 193, 191, 242, 189, 288, 224, 253, 292, 308, 318, 254, 303, 331, 414, 389, 405, 373, 479, 436, 425, 504, 537, 499, 523, 543, 498, 600, 546, 584, 643, 640, 656, 626, 663 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

MATHEMATICA

a = {}; Do[k = 1; While[ Count[ IntegerDigits[4^k], 6] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a

Log[4, #]&/@Table[First[Select[4^Range[900], DigitCount[#, 10, 6]==n&]], {n, 0, 60}] (* Harvey P. Dale, May 15 2011 *)

CROSSREFS

Sequence in context: A065131 A192157 A268810 * A293296 A055044 A067051

Adjacent sequences:  A063578 A063579 A063580 * A063582 A063583 A063584

KEYWORD

base,nonn

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 2 09:21 EDT 2020. Contains 335398 sequences. (Running on oeis4.)