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A034171 Related to triple factorial numbers A007559(n+1). 10
1, 6, 42, 315, 2457, 19656, 160056, 1320462, 11003850, 92432340, 781473420, 6642524070, 56716936290, 486145168200, 4180848446520, 36059817851235, 311811366125385, 2702365173086670, 23467908082068450, 204170800313995515 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..19.

W. Lang, On generalizations of Stirling number triangles, J. Integer Seqs., Vol. 3 (2000), #00.2.4.

FORMULA

a(n) = 3^n*A007559(n+1)/(n+1)!, A007559(n+1)=(3*n+1)!!!; G.f.: (-1+(1-9*x)^(-1/3))/(3*x).

CROSSREFS

Cf. A007559, A034164. a(n)= A035529(n+1, 1) (first column of triangle).

Convolution of A004987(n) with A025748(n+1), n >= 0.

Sequence in context: A093388 A162968 A247638 * A264911 A244902 A153293

Adjacent sequences:  A034168 A034169 A034170 * A034172 A034173 A034174

KEYWORD

easy,nonn

AUTHOR

Wolfdieter Lang

STATUS

approved

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Last modified March 26 23:16 EDT 2019. Contains 321566 sequences. (Running on oeis4.)