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A367028
G.f. satisfies A(x) = 1 + x*A(x) - x^2*A(x)^3.
2
1, 1, 0, -3, -6, 2, 38, 77, -58, -658, -1240, 1562, 13064, 22076, -41710, -279427, -411418, 1114998, 6252048, 7758726, -29876900, -143956676, -143561972, 802102322, 3376515404, 2496314012, -21558225312, -80113377828, -37101814188, 579611761168
OFFSET
0,4
FORMULA
a(n) = Sum_{k=0..floor(n/2)} (-1)^k * binomial(n+k,k) * binomial(n,n-2*k) / (2*k+1).
PROG
(PARI) a(n) = sum(k=0, n\2, (-1)^k*binomial(n+k, k)*binomial(n, n-2*k)/(2*k+1));
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Nov 02 2023
STATUS
approved