A309954 Product of digits of (n written in base 4).

0, 1, 2, 3, 0, 1, 2, 3, 0, 2, 4, 6, 0, 3, 6, 9, 0, 0, 0, 0, 0, 1, 2, 3, 0, 2, 4, 6, 0, 3, 6, 9, 0, 0, 0, 0, 0, 2, 4, 6, 0, 4, 8, 12, 0, 6, 12, 18, 0, 0, 0, 0, 0, 3, 6, 9, 0, 6, 12, 18, 0, 9, 18, 27, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 0, 2, 4, 6, 0, 3, 6, 9, 0, 0, 0, 0, 0

Offset: 0

Author

Ilya Gutkovskiy, Aug 24 2019

Keywords

• nonn
• base

Links

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

Crossrefs

Cf. A007090, A007954, A053737.

Programs

Mathematica

Table[Times @@ IntegerDigits[n, 4], {n, 0, 100}]

Formula

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