OFFSET
1,1
EXAMPLE
a(2)=121645100408832000 so 121645100408832000 is the smallest factorial containing exactly two 4's.
MATHEMATICA
Table[SelectFirst[Table[With[{c=n!}, {c, DigitCount[c, 10, 4]}], {n, 100}], #[[2]] == k&], {k, 8}][[All, 1]] (* Harvey P. Dale, Nov 18 2021 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Shyam Sunder Gupta, Jul 30 2002
EXTENSIONS
More terms from Harvey P. Dale, Nov 18 2021
STATUS
approved