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 A051609 a(n) = (3*n+9)!!!/9!!!, related to A032031 ((3*n)!!! triple factorials). 8
 1, 12, 180, 3240, 68040, 1632960, 44089920, 1322697600, 43649020800, 1571364748800, 61283225203200, 2573895458534400, 115825295634048000, 5559614190434304000, 283540323712149504000, 15311177480456073216000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Row m=9 of the array A(4; m,n) := ((3*n+m)(!^3))/m(!^3), m >= 0, n >= 0. LINKS G. C. Greubel, Table of n, a(n) for n = 0..377 FORMULA a(n) = ((3*n+9)(!^3))/9(!^3). E.g.f.: 1/(1-3*x)^4. MAPLE restart: G(x):=(1-3*x)^(n-5): f[0]:=G(x): for n from 1 to 29 do f[n]:=diff(f[n-1], x) od:x:=0:seq(f[n], n=0..15); # Zerinvary Lajos, Apr 04 2009 MATHEMATICA With[{nn = 30}, CoefficientList[Series[1/(1 - 3*x)^(12/3), {x, 0, nn}], x]*Range[0, nn]!] (* G. C. Greubel, Aug 15 2018 *) PROG (PARI) x='x+O('x^30); Vec(serlaplace(1/(1-3*x)^(12/3))) \\ G. C. Greubel, Aug 15 2018 (MAGMA) m:=30; R:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!(1/(1-3*x)^(12/3))); [Factorial(n-1)*b[n]: n in [1..m]]; // G. C. Greubel, Aug 15 2018 CROSSREFS Cf. A032031, A007559(n+1), A034000(n+1), A034001(n+1), A051604-A051608 (rows m=0..8). Sequence in context: A000515 A241710 A318245 * A001814 A327079 A013924 Adjacent sequences:  A051606 A051607 A051608 * A051610 A051611 A051612 KEYWORD easy,nonn AUTHOR STATUS approved

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Last modified May 31 00:53 EDT 2020. Contains 334747 sequences. (Running on oeis4.)