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A370891
G.f. satisfies A(x) = ( 1 + x * A(x)^(1/4) * (1 + A(x)^(3/4)) )^2.
2
1, 4, 14, 52, 205, 844, 3588, 15632, 69434, 313264, 1431650, 6613732, 30834548, 144895284, 685566370, 3263309844, 15616322995, 75085908112, 362563417968, 1757412095456, 8548129677400, 41710100368160, 204110896990686, 1001480947876276, 4925833177966164
OFFSET
0,2
FORMULA
G.f.: B(x)^4 where B(x) is the g.f. of A106228.
a(n) = 2 * Sum_{k=0..n} binomial(n,k) * binomial(n/2+3*k/2+2,n)/(n/2+3*k/2+2).
PROG
(PARI) a(n) = 2*sum(k=0, n, binomial(n, k)*binomial(n/2+3*k/2+2, n)/(n/2+3*k/2+2));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Apr 04 2024
STATUS
approved