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 A129239 #8 May 29 2023 13:00:42 %S A129239 1,1,0,3,2,0,4,0,3,0,10,5,3,4,0,6,0,0,0,5,0,21,9,7,4,5,6,0,16,0,3,0,5, %T A129239 0,7,0,27,10,0,9,5,0,7,8,0,20,0,8,0,0,0,7,0,9,0,55,20,12,9,11,6,7,8,9, %U A129239 10,0,24,0,0,0,5,0,7,0,0,0,11,0,78,27,18,15,11,13,7,8,9,10,11,12,0 %N A129239 Triangle read by rows: A054521 * A129234 as infinite lower triangular matrices. %C A129239 Left column = A023896: (1, 1, 3, 4, 10, 6, 21, ...). %e A129239 First few rows of the triangle: %e A129239 1; %e A129239 1, 0; %e A129239 3, 2, 0; %e A129239 4, 0, 3, 0; %e A129239 10, 5, 3, 4, 0; %e A129239 6, 0, 0, 0, 5, 0; %e A129239 21, 9, 7, 4, 5, 6, 0; %e A129239 16, 0, 3, 0, 5, 0, 7, 0; %e A129239 ... %Y A129239 Cf. A023896, A054521, A129234. %K A129239 nonn,tabl %O A129239 1,4 %A A129239 _Gary W. Adamson_, Apr 05 2007 %E A129239 a(21) = 0 inserted and more terms from _Georg Fischer_, May 29 2023