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G.f. satisfies A(x) = (1 + x) * (1 + x*A(x)^4).
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%I #12 Jul 20 2023 09:19:10

%S 1,2,9,68,580,5406,53270,545844,5757332,62094217,681653493,7591431752,

%T 85558696024,974024788280,11184192097016,129378232148016,

%U 1506363564912368,17639001584452320,207593804132718948,2454236122156830254,29132714097692056954,347086786035103983446

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

%H Seiichi Manyama, <a href="/A364337/b364337.txt">Table of n, a(n) for n = 0..907</a>

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

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

%Y Cf. A073157, A364336, A364338, A364339.

%Y Cf. A215623, A215715, A234461, A239107.

%K nonn

%O 0,2

%A _Seiichi Manyama_, Jul 19 2023