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 A299501 #10 Jan 30 2020 21:29:18
%S A299501 1,3,10,37,145,588,2437,10251,43582,186785,805585,3492064,15200753,
%T A299501 66399763,290910490,1277803957,5625184321,24811849020,109631120869,
%U A299501 485153695995,2149941422590,9539307910561,42374000475457,188421560848512,838633172823745,3735857124917763
%N A299501 Expansion of (1 - 6*x + 7*x^2 - 2*x^3 + x^4)^(-1/2).
%C A299501 See A299500 for a family of related polynomials.
%F A299501 a(n) = Sum_{k=0..n} 2^(n-k)*binomial(n, k)*hypergeom([-k, k-n, k-n], [1, -n], 1/2).
%F A299501 D-finite with recurrence: (-2+n)*a(-4+n) + (-2*n+3)*a(n-3) + (7*n-7)*a(-2+n) + (-6*n+3)*a(-1+n) + n*a(n) = 0.
%F A299501 A249946(n) = a(n) - 2*a(n-1) + a(n-2) for n >= 2.
%p A299501 a := n -> add(2^(n-k)*binomial(n, k)*hypergeom([-k, k-n, k-n], [1, -n], 1/2), k=0..n): seq(simplify(a(n)), n=0..25);
%t A299501 CoefficientList[Series[(1 - 6 x + 7 x^2 - 2 x^3 + x^4 )^(-1/2), {x, 0, 25}], x]
%Y A299501 Cf. A249946, A299500.
%K A299501 nonn
%O A299501 0,2
%A A299501 _Peter Luschny_, Feb 15 2018