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 A299864 #10 Jul 05 2018 05:17:39
%S A299864 1,1,19,239,3011,38435,496365,6470385,84975315,1122708899,14906800361,
%T A299864 198740733581,2658870294349,35677678567549,479965685669059,
%U A299864 6471364940381007,87425255326277907,1183139999323074963,16036589185819644633,217668383345249016045
%N A299864 a(n) = (-1)^n*hypergeom([-n, n - 1/2], [1], 4).
%H A299864 Robert Israel, <a href="/A299864/b299864.txt">Table of n, a(n) for n = 0..875</a>
%F A299864 From _Robert Israel_, Mar 21 2018: (Start)
%F A299864 a(n) = JacobiP(n,0,-3/2,-7).
%F A299864 n*(2*n-3)*(4*n-7)*a(n)+(2*n-5)*(n-1)*(4*n-3)*a(n-2)-(4*n-5)*(28*n^2-70*n+39)*a(n-1) = 0. (End)
%F A299864 a(n) ~ sqrt(3) * (1 + sqrt(3))^(4*n - 1) / (2^(2*n + 1) * sqrt(Pi*n)). - _Vaclav Kotesovec_, Jul 05 2018
%p A299864 seq((-1)^n*orthopoly[P](n,0,-3/2,-7),n=0..100); # _Robert Israel_, Mar 21 2018
%t A299864 a[n_] := (-1)^n Hypergeometric2F1[-n, n - 1/2, 1, 4]; Table[a[n], {n, 0, 19}]
%Y A299864 Cf. A299507, A245926, A084768, A245927.
%Y A299864 Cf. A300945, A300946.
%K A299864 nonn
%O A299864 0,3
%A A299864 _Peter Luschny_, Mar 16 2018