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 A033926 #14 Nov 03 2022 16:35:25
%S A033926 1,1,2,3,4,5,1,2,3,4,5,6,2,3,4,5,6,7,3,4,5,6,7,8,4,5,6,7,8,9,5,6,7,8,
%T A033926 9,10,2,3,4,5,6,7,3,4,5,6,7,8,4,5,6,7,8,9,5,6,7,8,9,10,6,7,8,9,10,11,
%U A033926 7,8,9,10,11,12,4,5,6,7,8,9,5,6,7,8,9,10,6,7,8,9,10,11,7,8,9,10,11,12,8,9
%N A033926 Base 6 digital convolution sequence.
%H A033926 Michael De Vlieger, <a href="/A033926/b033926.txt">Table of n, a(n) for n = 0..7776</a>
%e A033926 181 = 501 in base 6, so a(181) = 5*a(2)+0*a(1)+1*a(0) = 5*2+0+1 = 11.
%t A033926 nn = 90; a[0] = 1; Do[k = Total@ MapIndexed[#1 a[First[#2] - 1] &, Reverse@ IntegerDigits[n, 6]]; a[n] = k, {n, nn}]; Array[a, nn + 1, 0] (* _Michael De Vlieger_, Nov 03 2022 *)
%o A033926 (PARI) a(n) = if (n, my(d=digits(n, 6)); sum(k=1, #d, d[k]*a(#d-k)), 1); \\ _Michel Marcus_, Nov 03 2022
%Y A033926 Cf. A007092.
%Y A033926 Cf. A033922, A033923, A033924, A033925, A033927, A033928, A033929, A033930.
%K A033926 nonn,base
%O A033926 0,3
%A A033926 _David W. Wilson_
%E A033926 Offset 0 from _Michel Marcus_, Nov 03 2022