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 A371697 #4 Apr 04 2024 10:31:48
%S A371697 1,2,11,113,1732,35509,914213,28372686,1031486867,43009596241,
%T A371697 2023804597256,106098215717113,6133027601141401,387563995785510010,
%U A371697 26581805841852520619,1966679438751901515329,156133093759166939659212,13239463980230688450540781,1194277034550296812912993853
%N A371697 Row sums of triangle A370262.
%F A371697 a(n) = Sum_{k = 0..n} binomial(n+k, n-k)/(2*k+1) * (2*n+1)^k
%F A371697 a(n)^2 = 2/(2*n + 1)^3 * (T(2*n+1, n+3/2) - 1), where T(n, x) denotes the n-th Chebyshev polynomial of the first kind.
%p A371697 seq(add(binomial(n+k, n-k)/(2*k+1) * (2*n+1)^k, k = 0..n), n = 0..20);
%Y A371697 Cf. A370262.
%K A371697 nonn,easy
%O A371697 0,2
%A A371697 _Peter Bala_, Apr 03 2024