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G.f. satisfies A(x) = 1 + x / (1 + x*A(x))^5.
4

%I #9 Aug 22 2023 07:57:03

%S 1,1,-5,10,20,-220,624,940,-15220,52090,49310,-1254070,4951430,

%T 2039640,-113088840,505430700,-42379684,-10748423405,53899438385,

%U -29300595085,-1054751754795,5914944193114,-5760460624890,-105478270711140,661900612108440,-914408777470140

%N G.f. satisfies A(x) = 1 + x / (1 + x*A(x))^5.

%F If g.f. satisfies A(x) = 1 + x/(1 + x*A(x))^s, then a(n) = Sum_{k=0..n} (-1)^(n-k) * binomial(n-k+1,k) * binomial(n+(s-1)*k-1,n-k)/(n-k+1).

%o (PARI) a(n, s=5) = sum(k=0, n, (-1)^(n-k)*binomial(n-k+1, k)*binomial(n+(s-1)*k-1, n-k)/(n-k+1));

%Y Cf. A007440, A365109, A365110, A365111.

%Y Cf. A365088.

%K sign

%O 0,3

%A _Seiichi Manyama_, Aug 22 2023