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 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

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Last modified May 27 13:04 EDT 2022. Contains 354097 sequences. (Running on oeis4.)