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A369722 Expansion of e.g.f. exp( (3/2) * (1-sqrt(1-4*x)) ). 3
1, 3, 15, 117, 1305, 19323, 359559, 8084205, 213425361, 6475518675, 222088463199, 8497641269637, 358899729493545, 16585866328129803, 832523413971932055, 45105537151437499197, 2623613865509122341921, 163070009495928522691875 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
FORMULA
a(0) = 1; a(n) = Sum_{k=0..n-1} 3^(n-k) * (n-1+k)! / (k! * (n-1-k)!).
a(n) = 2*(2*n-3)*a(n-1) + 9*a(n-2).
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(exp(3/2*(1-sqrt(1-4*x)))))
CROSSREFS
Cf. A000108.
Sequence in context: A080290 A365777 A372161 * A259843 A136654 A364621
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jan 30 2024
STATUS
approved

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Last modified April 22 02:54 EDT 2024. Contains 371887 sequences. (Running on oeis4.)