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 A321399 #3 Nov 08 2018 18:06:27 %S A321399 1,1,2,3,6,17,70,401,2969,27140,296824,3805050,56375499,955491092, %T A321399 18372395618,397763836270,9625919876062,258564672432833, %U A321399 7659052858050807,248738123007194830,8812695551133726251,339191479636896892415,14131494196304254373334 %N A321399 Antidiagonal sums of A321400. %p A321399 # Function A321400Row defined in A321400. %p A321399 seq(add(A321400Row(k, 24)[n-k+1], k=0..n), n=0..22); %Y A321399 Cf. A321400. %K A321399 nonn %O A321399 0,3 %A A321399 _Peter Luschny_, Nov 08 2018