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 A104431 #16 Nov 24 2023 09:41:32 %S A104431 1,1,2,4,10,21,59,125,349,848,2224,5210,15720,37096,98241,245251, %T A104431 684475,1703174,4915084,12024901,33594399 %N A104431 Number of ways to split 1, 2, 3, ..., 5n into n arithmetic progressions each with 5 terms. %Y A104431 Cf. A104429-A104430, A104432-A104443, A349430. %K A104431 nonn,more %O A104431 0,3 %A A104431 _Jonas Wallgren_, Mar 17 2005 %E A104431 a(11)-a(18) from _Alois P. Heinz_, Dec 28 2011 %E A104431 a(19)-a(20) from _Alois P. Heinz_, Nov 18 2021