A001806 a(n) = n! * binomial(n,4).
24, 600, 10800, 176400, 2822400, 45722880, 762048000, 13172544000, 237105792000, 4452319872000, 87265469491200, 1784975512320000, 38079477596160000, 846536078868480000, 19591263539527680000, 471496409184632832000, 11787410229615820800000
Offset: 4
Keywords
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. 799.
- 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
- T. D. Noe, Table of n, a(n) for n = 4..100
- 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].
- Index entries for sequences related to Laguerre polynomials
Crossrefs
A column of triangle A021012.
Programs
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Magma
[Factorial(n)*Binomial(n,4): n in [4..30]]; // G. C. Greubel, May 17 2018
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Maple
G(x):=x^4/(1-x)^5: f[0]:=G(x): for n from 1 to 18 do f[n]:=diff(f[n-1],x) od: x:=0: seq(f[n],n=4..18); # Zerinvary Lajos, Apr 01 2009
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Mathematica
Table[n! Binomial[n, 4], {n, 4, 20}] (* T. D. Noe, Aug 10 2012 *) -
PARI
for(n=4,30, print1(n!*binomial(n,4), ", ")) \\ G. C. Greubel, May 17 2018
Formula
E.g.f.: x^4/(1-x)^5. - Geoffrey Critzer, Aug 19 2012
Extensions
More terms from Ralf Stephan, Jan 09 2004
Comments