OFFSET
6,4
COMMENTS
(sum of digits of n!) / 9 is an integer for n > 5.
LINKS
Seiichi Manyama, Table of n, a(n) for n = 6..10000
FORMULA
a(n) = A004152(n)/9.
MATHEMATICA
Table[Sum[DigitCount[n!][[i]]*i/9, {i, 1, 9}], {n, 6, 100}]
Total[IntegerDigits[#]]/9&/@(Range[6, 80]!) (* Harvey P. Dale, Nov 22 2023 *)
PROG
(PARI) a(n) = sumdigits(n!)/9; \\ Michel Marcus, Aug 12 2022
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Michel Lagneau, Dec 23 2011
STATUS
approved