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A063635
Smallest k such that 9^k has exactly n 9's in its decimal representation.
0
2, 1, 5, 15, 25, 18, 41, 56, 51, 69, 66, 102, 87, 137, 88, 116, 100, 117, 135, 151, 129, 110, 190, 139, 187, 210, 236, 253, 218, 261, 264, 257, 301, 318, 312, 303, 285, 335, 291, 337, 300, 310, 384, 351, 390, 362, 374, 405, 413, 435, 436
OFFSET
0,1
MATHEMATICA
a = {}; Do[k = 1; While[ Count[ IntegerDigits[9^k], 9] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a
Module[{nn=500, tbl}, tbl=Table[{n, DigitCount[9^n, 10, 9]}, {n, nn}]; Table[SelectFirst[ tbl, #[[2]] == k&], {k, 0, 50}]][[All, 1]] (* Harvey P. Dale, Jan 06 2023 *)
CROSSREFS
Sequence in context: A144237 A350742 A268295 * A192264 A144054 A144058
KEYWORD
base,nonn
AUTHOR
Robert G. Wilson v, Aug 10 2001
EXTENSIONS
Name corrected by Jon E. Schoenfield, Jun 26 2018
STATUS
approved