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A363578 G.f. satisfies A(x) = exp( Sum_{k>=1} ((-2)^k + A(x^k)) * x^k/k ). 2
1, -1, 2, -2, 4, -6, 13, -20, 38, -65, 129, -228, 435, -794, 1528, -2833, 5421, -10189, 19561, -37091, 71247, -135973, 261879, -502303, 969181, -1866210, 3608664, -6970576, 13504298, -26152744, 50758711, -98515611, 191517618, -372404560, 725061378 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
FORMULA
A(x) = B(x)/(1 + 2*x) where B(x) is the g.f. of A363580.
A(x) = Sum_{k>=0} a(k) * x^k = 1/(1+2*x) * 1/Product_{k>=0} (1-x^(k+1))^a(k).
a(0) = 1; a(n) = (1/n) * Sum_{k=1..n} ( (-2)^k + Sum_{d|k} d * a(d-1) ) * a(n-k).
PROG
(PARI) seq(n) = my(A=1); for(i=1, n, A=exp(sum(k=1, i, ((-2)^k+subst(A, x, x^k))*x^k/k)+x*O(x^n))); Vec(A);
CROSSREFS
Cf. A363580.
Sequence in context: A188538 A282164 A268175 * A209025 A346779 A153955
KEYWORD
sign
AUTHOR
Seiichi Manyama, Jun 10 2023
STATUS
approved

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Last modified June 22 06:24 EDT 2024. Contains 373565 sequences. (Running on oeis4.)