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A364410
G.f. A(x) satisfies A(x) = 1 + x^2 * (A(x) / (1 - x))^4.
2
1, 0, 1, 4, 14, 52, 201, 800, 3260, 13536, 57068, 243664, 1051512, 4579088, 20097526, 88810872, 394811696, 1764477304, 7923087616, 35728412152, 161731039076, 734646128920, 3347600839252, 15298276784648, 70097391229500, 321974115549256, 1482242974320685
OFFSET
0,4
FORMULA
a(n) = Sum_{k=0..floor(n/2)} binomial(n+2*k-1,n-2*k) * binomial(4*k,k) / (3*k+1).
PROG
(PARI) a(n) = sum(k=0, n\2, binomial(n+2*k-1, n-2*k)*binomial(4*k, k)/(3*k+1));
CROSSREFS
Partial sums give A186996.
Sequence in context: A244935 A199698 A052710 * A262594 A345242 A370891
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Oct 15 2023
STATUS
approved