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G.f. satisfies A(x) = ( 1 + x*A(x)^(5/2) / (1 - x) )^2.
2

%I #18 Mar 30 2024 02:37:42

%S 1,2,13,104,940,9166,94044,1000602,10939780,122161128,1387361151,

%T 15974899766,186069556707,2188416960148,25953579753464,

%U 310022550197360,3726709235290628,45047517497268968,547217895030263028,6676784544374859088,81789906534091716353

%N G.f. satisfies A(x) = ( 1 + x*A(x)^(5/2) / (1 - x) )^2.

%H Seiichi Manyama, <a href="/A371583/b371583.txt">Table of n, a(n) for n = 0..896</a>

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

%F G.f.: A(x) = B(x)^2 where B(x) is the g.f. of A349332.

%o (PARI) a(n, r=2, s=1, t=5, u=0) = r*sum(k=0, n, binomial(t*k+u*(n-k)+r, k)*binomial(n+(s-1)*k-1, n-k)/(t*k+u*(n-k)+r));

%Y Cf. A045868, A270386, A371518, A371523.

%Y Cf. A349332, A371486, A371520.

%Y Cf. A371578, A371585.

%K nonn

%O 0,2

%A _Seiichi Manyama_, Mar 28 2024