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 A383536 #7 Apr 29 2025 08:54:48
%S A383536 1,1,10,33,301,1468,12006,70945,548218,3588451,27033942,187329660,
%T A383536 1398372925,10015968040,74666604910,545706810657,4076875022533,
%U A383536 30186038308420,226302738440884,1690539173230083,12722171581599588,95650154853862786,722460110890588300
%N A383536 a(n) = Sum_{k=0..floor(n/2)} binomial(n+k,k)^2 * binomial(n-k,k).
%C A383536 Diagonal of the rational function 1 / ((1-x)*(1-y)*(1-z) - z^2).
%o A383536 (PARI) a(n) = sum(k=0, n\2, binomial(n+k, k)^2*binomial(n-k, k));
%Y A383536 Cf. A112019.
%K A383536 nonn
%O A383536 0,3
%A A383536 _Seiichi Manyama_, Apr 29 2025