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A001194 Expansion of an integral.
(Formerly M2826 N1139)
0
3, 9, 54, 450, 4725, 59535, 873180, 14594580, 273648375, 5685805125, 129636356850, 3217338674550, 86331921100425, 2490343877896875, 76844896803675000, 2525635608280785000, 88081541838792376875, 3248654513701342370625 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

REFERENCES

L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 167.

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Table of n, a(n) for n=2..19.

FORMULA

a(n)=(2n-1)a(n-1)-3(n-1)(2n-7)!!, n>2. [Sean A. Irvine, Mar 23 2012]

a(n) = 3*n*(n-1)*(2*n-4)!/(2^(n-1)*(n-2)!), n>=2. - Vaclav Kotesovec, Jan 05 2014

MATHEMATICA

Table[3*n*(n-1)*(2*n-4)!/(2^(n-1)*(n-2)!), {n, 2, 20}] (* Vaclav Kotesovec, Jan 05 2014 *)

CROSSREFS

Sequence in context: A238906 A212418 A025226 * A032179 A233189 A175117

Adjacent sequences:  A001191 A001192 A001193 * A001195 A001196 A001197

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Sean A. Irvine, Mar 22 2012

STATUS

approved

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Last modified October 24 12:34 EDT 2014. Contains 248516 sequences.