A300659 Product of digits of n!.

1, 1, 2, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset

0,3

Comments

Also multiplicative digital root of n!.

Decimal expansion of 2817/25000. - Eric Chen, Jun 06 2018

Links

Table of n, a(n) for n=0..86.

Index entries for linear recurrences with constant coefficients, signature (1).

Formula

G.f.: 1 + x + 2*x^2 + 6*x^3 + 8*x^4.

a(n) = 0 for n >= 5.

a(n) = A031347(A000142(n)).

a(n) = A007954(A000142(n)). - Eric Chen, Jun 06 2018

Mathematica

Array[Times @@ IntegerDigits[#!] &, 105] (* Michael De Vlieger, Jun 06 2018 *)

Prog

(Magma) [&*Intseq(Factorial(n)): n in [0..100]];
(PARI) a(n) = my(d=digits(n!)); prod(k=1, #d, d[k]); \\ Michel Marcus, Jun 05 2018

Crossrefs

Cf. A000142, A007954, A031347, A067067, A086358, A004152.

Sequence in context: A366061 A057249 A246120 * A155003 A327279 A021377

Adjacent sequences: A300656 A300657 A300658 * A300660 A300661 A300662

Keyword

nonn,base,easy

Author

Jaroslav Krizek, Jun 05 2018

Status

approved