A338803 Product of the nonzero digits of (n written in base 5).

1, 1, 2, 3, 4, 1, 1, 2, 3, 4, 2, 2, 4, 6, 8, 3, 3, 6, 9, 12, 4, 4, 8, 12, 16, 1, 1, 2, 3, 4, 1, 1, 2, 3, 4, 2, 2, 4, 6, 8, 3, 3, 6, 9, 12, 4, 4, 8, 12, 16, 2, 2, 4, 6, 8, 2, 2, 4, 6, 8, 4, 4, 8, 12, 16, 6, 6, 12, 18, 24, 8, 8, 16, 24, 32, 3, 3, 6, 9, 12, 3

Offset

0,3

Links

Table of n, a(n) for n=0..80.

Formula

G.f. A(x) satisfies: A(x) = (1 + x + 2*x^2 + 3*x^3 + 4*x^4) * A(x^5).

Mathematica

Table[Times @@ DeleteCases[IntegerDigits[n, 5], 0], {n, 0, 80}]
nmax = 80; A[_] = 1; Do[A[x_] = (1 + x + 2 x^2 + 3 x^3 + 4 x^4) A[x^5] + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]

Prog

(PARI) a(n) = vecprod(select(x->x, digits(n, 5))); \\ Michel Marcus, Nov 12 2020

Crossrefs

Cf. A007091, A051801, A117592, A309956.

Sequence in context: A139458 A277543 A190594 * A104412 A195451 A298160

Adjacent sequences: A338800 A338801 A338802 * A338804 A338805 A338806

Keyword

nonn,base

Author

Ilya Gutkovskiy, Nov 12 2020

Status

approved