OFFSET
1,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..500
MATHEMATICA
a = {}; Do[k = 1; While[ Count[ IntegerDigits[5^k], 5] != n, k++ ]; a = Append[a, k], {n, 1, 50} ]; a
With[{tbl=Table[{k, DigitCount[5^k, 10, 5]}, {k, 600}]}, Table[SelectFirst[tbl, #[[2]]==n&], {n, 50}]][[;; , 1]] (* This program is many times more efficient than the first Mathematica program above. *) (* Harvey P. Dale, Dec 13 2024 *)
CROSSREFS
KEYWORD
base,nonn,changed
AUTHOR
Robert G. Wilson v, Aug 10 2001
EXTENSIONS
Name corrected by Jon E. Schoenfield, Jun 26 2018
STATUS
approved