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 A385624 #12 Jul 09 2025 23:50:50
%S A385624 0,11,33,66,110,165,231,308,396,495,605,816,1128,1541,2055,2670,3386,
%T A385624 4203,5121,6140,7260,8481,9803,11226,12750,14375,16101,17928,19856,
%U A385624 21885,24015,26246,28578,31011,33545,36180,38916,41753,44691,47730,50870,54111,57453,60896
%N A385624 Antidiagonal sums of the array defined in A385623.
%H A385624 Stefano Spezia, <a href="/A385624/b385624.txt">Table of n, a(n) for n = 0..2000</a>
%t A385624 A385623[n_,k_]:=If[k==0,10n,n*10^(Floor[Log10[k]]+1)+k]; a[n_]:=Sum[A385623[n-k,k],{k,0,n}]; Array[a,44,0]
%o A385624 (PARI) T(n, k) = if (k==0, 10*n, fromdigits(concat(digits(n), digits(k)))); \\ A385623
%o A385624 a(n) = sum(i=0, n, T(i, n-i)); \\ _Michel Marcus_, Jul 06 2025
%Y A385624 Cf. A385623.
%K A385624 nonn,base
%O A385624 0,2
%A A385624 _Stefano Spezia_, Jul 05 2025