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A063607
Smallest k such that 7^k has exactly n 1's in its decimal representation.
0
1, 4, 6, 12, 19, 34, 24, 37, 38, 57, 52, 92, 96, 88, 116, 142, 133, 156, 108, 147, 115, 158, 209, 190, 180, 266, 200, 270, 240, 262, 263, 208, 279, 366, 339, 304, 352, 331, 406, 316, 407, 385, 396, 434, 437, 376, 386, 414, 470, 450, 551
OFFSET
0,2
MATHEMATICA
a = {}; Do[k = 1; While[ Count[ IntegerDigits[7^k], 1] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a
Table[Position[DigitCount[7^Range[600], 10, 1], n, 1, 1], {n, 0, 50}]//Flatten (* Harvey P. Dale, Jan 12 2019 *)
CROSSREFS
Sequence in context: A048641 A023599 A087881 * A306270 A045956 A057339
KEYWORD
base,nonn
AUTHOR
Robert G. Wilson v, Aug 10 2001
EXTENSIONS
Name corrected by Jon E. Schoenfield, Jun 26 2018
STATUS
approved