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 A309959 #15 Sep 08 2022 08:46:22
%S A309959 0,1,2,3,4,5,6,7,0,1,2,3,4,5,6,7,0,2,4,6,8,10,12,14,0,3,6,9,12,15,18,
%T A309959 21,0,4,8,12,16,20,24,28,0,5,10,15,20,25,30,35,0,6,12,18,24,30,36,42,
%U A309959 0,7,14,21,28,35,42,49,0,0,0,0,0,0,0,0,0,1,2,3,4,5,6,7,0,2,4,6,8,10,12,14,0,3,6,9,12,15,18,21,0,4,8,12,16
%N A309959 Product of digits of (n written in base 8).
%H A309959 Seiichi Manyama, <a href="/A309959/b309959.txt">Table of n, a(n) for n = 0..10000</a>
%F A309959 G.f. A(x) satisfies: A(x) = x * (1 + 2*x + 3*x^2 + 4*x^3 + 5*x^4 + 6*x^5 + 7*x^6) * (1 + A(x^8)).
%t A309959 Table[Times @@ IntegerDigits[n, 8], {n, 0, 100}]
%o A309959 (Magma) [0] cat [&*Intseq(n,8):n in [1..100]]; // _Marius A. Burtea_, Aug 25 2019
%Y A309959 Product of digits of (n written in base k): A309953 (k = 3), A309954 (k = 4), A309956 (k = 5), A309957 (k = 6), A309958 (k = 7), this sequence (k = 8), A309788 (k = 9), A007954 (k = 10).
%Y A309959 Cf. A007094, A053829.
%K A309959 nonn,base
%O A309959 0,3
%A A309959 _Ilya Gutkovskiy_, Aug 24 2019