This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A338803 #10 Nov 13 2020 14:22:26
%S A338803 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,
%T A338803 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,
%U A338803 6,6,12,18,24,8,8,16,24,32,3,3,6,9,12,3
%N A338803 Product of the nonzero digits of (n written in base 5).
%F A338803 G.f. A(x) satisfies: A(x) = (1 + x + 2*x^2 + 3*x^3 + 4*x^4) * A(x^5).
%t A338803 Table[Times @@ DeleteCases[IntegerDigits[n, 5], 0], {n, 0, 80}]
%t A338803 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]
%o A338803 (PARI) a(n) = vecprod(select(x->x, digits(n, 5))); \\ _Michel Marcus_, Nov 12 2020
%Y A338803 Cf. A007091, A051801, A117592, A309956.
%K A338803 nonn,base
%O A338803 0,3
%A A338803 _Ilya Gutkovskiy_, Nov 12 2020