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A004332
a(n) = C(4n,n-2).
2
1, 12, 120, 1140, 10626, 98280, 906192, 8347680, 76904685, 708930508, 6540715896, 60403728840, 558383307300, 5166863427600, 47855699958816, 443643407165376, 4116305022165108, 38223742100828400, 355214207837288800
OFFSET
2,2
REFERENCES
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 828.
LINKS
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
FORMULA
G.f.: g*(g-1)^2/(4-3*g) where g = 1+x*g^4 is the g.f. of A002293. - Mark van Hoeij, Nov 17 2011
-3*(3*n+2)*(n-2)*(3*n+1)*a(n) + 8*(4*n-3)*(2*n-1)*(4*n-1)*a(n-1) = 0. - R. J. Mathar, May 27 2014
MATHEMATICA
Table[Binomial[4n, n-2], {n, 2, 20}] (* Harvey P. Dale, Apr 11 2011 *)
PROG
(PARI) a(n) = binomial(4*n, n-2); \\ Michel Marcus, May 10 2020
CROSSREFS
Cf. A002293.
Sequence in context: A291391 A115902 A277491 * A129329 A266393 A129332
KEYWORD
nonn,easy
STATUS
approved