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A063579
Smallest k such that 4^k has exactly n 4's in its decimal representation.
1
2, 1, 9, 11, 32, 53, 64, 75, 82, 69, 91, 134, 144, 161, 189, 133, 132, 198, 192, 253, 225, 219, 268, 236, 284, 252, 255, 374, 296, 315, 355, 372, 404, 421, 414, 450, 361, 538, 501, 471, 459, 482, 533, 544, 445, 666, 640, 586, 615, 565, 665
OFFSET
0,1
MATHEMATICA
a = {}; Do[k = 1; While[ Count[ IntegerDigits[4^k], 4] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a
CROSSREFS
Sequence in context: A295851 A368375 A192324 * A240085 A078623 A198204
KEYWORD
base,nonn
AUTHOR
Robert G. Wilson v, Aug 10 2001
EXTENSIONS
Name corrected by Jon E. Schoenfield, Jun 26 2018
STATUS
approved