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A372250
E.g.f. A(x) satisfies A(x) = exp( x * A(x) * (1 + x^2 * A(x)) ).
1
1, 1, 3, 22, 221, 2796, 44527, 857074, 19250457, 494672824, 14331709691, 462277166814, 16430392693717, 638087135544340, 26885810437578471, 1221643263680551786, 59548603124180235953, 3099741728641090867056, 171619335190080336331891
OFFSET
0,3
LINKS
FORMULA
a(n) = n! * Sum_{k=0..floor(n/3)} (n-k+1)^(n-2*k-1) / (k! * (n-3*k)!).
PROG
(PARI) a(n) = n!*sum(k=0, n\3, (n-k+1)^(n-2*k-1)/(k!*(n-3*k)!));
CROSSREFS
Cf. A362392.
Sequence in context: A079489 A190526 A141152 * A066573 A341476 A303190
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Apr 24 2024
STATUS
approved