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 A011365 #24 Dec 30 2024 03:57:39
%S A011365 1,-2,-3,-11,-49,-244,-1301,-7265,-41945,-248357,-1499838,-9202478,
%T A011365 -57204263,-359491066,-2280171089,-14578108497,-93850280001,
%U A011365 -607856133804,-3958143058643,-25897182540675,-170164359751174,-1122422557526850,-7429480035700452
%N A011365 Reciprocal of g.f. for A007863.
%H A011365 Seiichi Manyama, <a href="/A011365/b011365.txt">Table of n, a(n) for n = 0..500</a>
%F A011365 a(n) = -(Sum_{i=0..n} binomial(n+i-2,n-2)*binomial(n+i-1,n-i))/(n-1), n>1; a(0) = 1, a(1) = -2. - _Vladimir Kruchinin_, Feb 15 2013
%o A011365 (PARI) a(n) = if (n==0, 1, if (n==1, -2, -sum(i=0, n, binomial(n+i-2,n-2)*binomial(n+i-1,n-i))/(n-1))); \\ _Michel Marcus_, Dec 29 2018
%Y A011365 Cf. A007863.
%K A011365 sign
%O A011365 0,2
%A A011365 _N. J. A. Sloane_