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A367721 E.g.f. satisfies A(x) = exp(x*A(-x^2)). 2
1, 1, 1, -5, -23, 1, 601, 7771, 26545, -401183, -6965999, -42828389, 528611161, 15543020065, 141983039017, -2393449681349, -83586615493919, -708151768946879, 15447932991283105, 635290179334026427, 7146984268771158601, -162583738763505944639 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,4
LINKS
FORMULA
a(0) = 1; a(n) = (n-1)! * Sum_{k=0..floor((n-1)/2)} (-1)^k * (2*k+1) * a(k) * a(n-1-2*k) / (k! * (n-1-2*k)!).
PROG
(PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=(i-1)!*sum(j=0, (i-1)\2, (-1)^j*(2*j+1)*v[j+1]*v[i-2*j]/(j!*(i-1-2*j)!))); v;
CROSSREFS
Cf. A138292.
Sequence in context: A298233 A215742 A357948 * A282688 A282875 A317679
KEYWORD
sign
AUTHOR
Seiichi Manyama, Nov 28 2023
STATUS
approved

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Last modified April 16 18:02 EDT 2024. Contains 371750 sequences. (Running on oeis4.)