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G.f. satisfies A(x) = 1 - x*A(x)^4 * (1 - 3*A(x)).
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%I #18 Aug 09 2023 16:58:33

%S 1,2,22,338,6038,117570,2420758,51833106,1142472150,25749801986,

%T 590737764118,13748997055826,323842714201622,7704914865207362,

%U 184899022770465558,4470200057557410834,108776308617293352534,2662072268791363675650

%N G.f. satisfies A(x) = 1 - x*A(x)^4 * (1 - 3*A(x)).

%H Seiichi Manyama, <a href="/A364826/b364826.txt">Table of n, a(n) for n = 0..704</a>

%F a(n) = (-1)^n * Sum_{k=0..n} (-3)^k * binomial(n,k) * binomial(4*n+k+1,n) / (4*n+k+1).

%F a(n) = (1/n) * Sum_{k=0..n-1} 2^(n-k) * binomial(n,k) * binomial(5*n-k,n-1-k) for n > 0.

%F a(n) = (1/n) * Sum_{k=1..n} 2^k * 3^(n-k) * binomial(n,k) * binomial(4*n,k-1) for n > 0.

%o (PARI) a(n) = (-1)^n*sum(k=0, n, (-3)^k*binomial(n, k)*binomial(4*n+k+1, n)/(4*n+k+1));

%Y Cf. A025192, A107841, A235347, A364825, A364827.

%Y Cf. A243667, A260332.

%K nonn

%O 0,2

%A _Seiichi Manyama_, Aug 09 2023