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A004325
Binomial coefficient C(3n,n-7).
1
1, 24, 351, 4060, 40920, 376992, 3262623, 26978328, 215553195, 1677106640, 12777711870, 95722852680, 707285522580, 5166863427600, 37387265592825, 268367258592576, 1913212193400684, 13559593014190944
OFFSET
7,2
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
From Robert Israel, Jan 28 2018: (Start)
E.g.f.: x^7*hypergeom([22/3, 23/3], [11, 23/2], 27*x/4)/5040.
a(n+1) = (3*(3*n+1))*(3*n+2)*(n+1)/((2*(n+4))*(2*n+9)*(n-6))*a(n).
a(n) ~ sqrt(3/(Pi*n))*(27/4)^n/256 (End)
MAPLE
seq(binomial(3*n, n-7), n=7..50); # Robert Israel, Jan 28 2018
MATHEMATICA
Table[Binomial[3n, n-7], {n, 7, 30}] (* Harvey P. Dale, Dec 04 2014 *)
CROSSREFS
Sequence in context: A022748 A288968 A269029 * A075621 A293618 A137499
KEYWORD
nonn,easy
STATUS
approved