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A381209
Expansion of e.g.f. 1/(1 - x*cos(x))^3.
0
1, 3, 12, 51, 216, 735, 0, -39081, -575232, -6047973, -48314880, -189159333, 3046957056, 99745485879, 1789140627456, 23433663134655, 185580069027840, -1250544374605389, -94781673979379712, -2543434372808424957, -47763303489939701760, -586864592847636893937
OFFSET
0,2
COMMENTS
As stated in the comment of A185951, A185951(n,0) = 0^n.
FORMULA
a(n) = 1/2 * Sum_{k=0..n} (k+2)! * i^(n-k) * A185951(n,k), where i is the imaginary unit.
PROG
(PARI) a185951(n, k) = binomial(n, k)/2^k*sum(j=0, k, (2*j-k)^(n-k)*binomial(k, j));
a(n) = sum(k=0, n, (k+2)!*I^(n-k)*a185951(n, k))/2;
CROSSREFS
KEYWORD
sign,new
AUTHOR
Seiichi Manyama, Feb 17 2025
STATUS
approved