A079692 Number of 7's in n!.

0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 2, 2, 1, 1, 3, 0, 1, 2, 6, 2, 1, 0, 0, 1, 1, 3, 0, 4, 1, 1, 2, 2, 4, 3, 4, 4, 4, 3, 3, 4, 4, 4, 1, 2, 8, 5, 5, 3, 8, 5, 7, 4, 9, 4, 4, 7, 7, 6, 8, 8, 3, 9, 8, 6, 8, 8, 9, 10, 12, 7, 7, 9, 9, 7, 10, 10, 9, 14, 11, 12, 9, 7, 13, 17, 2, 11, 12, 19, 15, 12, 10, 15, 15, 16, 19, 7, 7, 12

Offset

0,15

Links

Seiichi Manyama, Table of n, a(n) for n = 0..10000

Index entries for sequences related to factorial numbers.

Formula

a(n) = A034886(n) - (A027869(n) + A079680(n) + A079714(n) + A079684(n) + A079688(n) + A079690(n) + A079691(n) + A079693(n) + A079694(n)). - Reinhard Zumkeller, Jan 27 2008

Maple

a:= n-> numboccur(7, convert(n!, base, 10)):
seq(a(n), n=0..101);  # Alois P. Heinz, Apr 26 2021

Prog

(PARI) a(n) = #select(x->(x==7), digits(n!)); \\ Michel Marcus, Apr 26 2021

Crossrefs

Cf. A079714.

Cf. A000142, A137579, A137580.

Cf. A316868.

Sequence in context: A110283 A226290 A235342 * A110269 A238280 A326644

Adjacent sequences: A079689 A079690 A079691 * A079693 A079694 A079695

Keyword

nonn,base,easy

Author

Cino Hilliard, Jan 31 2003

Extensions

a(78)-a(79) corrected by Georg Fischer, Apr 26 2021

Status

approved