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 A357510 #23 Oct 08 2022 10:09:02 %S A357510 0,4,108,3144,95000,2935020,92054340,2918972560,93330811440, %T A357510 3003683380020,97177865060540,3157623679795992,102973952434618824, %U A357510 3368460743291372092,110480459392323735540,3631941224582026770720,119637879389041977365600,3947968300820696313987780 %N A357510 a(n) = Sum_{k = 0..n} k * binomial(n,k)^2 * binomial(n+k,k)^2. %H A357510 Armin Straub, <a href="https://arxiv.org/abs/1401.0854">Multivariate Apéry numbers and supercongruences of rational functions</a>, arXiv:1401.0854 [math.NT] (2014). %F A357510 Conjecture: a(p-1) == 0 (mod p^4) for all primes p >= 5 (checked up to p = 499). %F A357510 Note: the Apery numbers A(n) = A005259(n) = Sum_{k = 0..n} binomial(n,k)^2 * binomial(n+k,k)^2 satisfy the supercongruence A(p-1) == 1 (mod p^3) for all primes p >= 5 (see, for example, Straub, Introduction). %F A357510 Recurrence: a(0) = 0, a(1) = 4, a(2) = 108 and thereafter n^2*(n-1)*(2*n-3)*(3*n^2-9*n+7)*a(n) = (2*n-1)*(105*n^5 - 576*n^4 + 1208*n^3 - 1195*n^2 + 556*n - 104)*a(n-1) - (2*n-3)*(105*n^5 - 474*n^4 + 800*n^3 - 629*n^2 + 240*n - 36)*a(n-2) + (n-1)*(2*n-1)*(3*n^2-3*n+1)*(n-2)^2*a(n-3). %F A357510 a(n) ~ (1 + sqrt(2))^(4*n + 2) / (2^(11/4) * Pi^(3/2) * sqrt(n)). - _Vaclav Kotesovec_, Oct 04 2022 %e A357510 a(11 - 1) = 97177865060540 = (2^2)*5*(11^4)*37*239*37529 == 0 (mod 11^4). %p A357510 seq( add( k*binomial(n,k)^2 * binomial(n+k,k)^2, k = 0..n ), n = 0..20 ); %o A357510 (PARI) a(n) = sum(k = 0, n, k * binomial(n,k)^2 * binomial(n+k,k)^2); \\ _Michel Marcus_, Oct 04 2022 %Y A357510 Cf. A005259, A357506, A357507, A357511, A357512, A357513. %K A357510 nonn,easy %O A357510 0,2 %A A357510 _Peter Bala_, Oct 01 2022