cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A005587 a(n) = n*(n+5)*(n+6)*(n+7)/24.

Original entry on oeis.org

0, 14, 42, 90, 165, 275, 429, 637, 910, 1260, 1700, 2244, 2907, 3705, 4655, 5775, 7084, 8602, 10350, 12350, 14625, 17199, 20097, 23345, 26970, 31000, 35464, 40392, 45815, 51765, 58275, 65379, 73112, 81510, 90610, 100450, 111069, 122507, 134805, 148005
Offset: 0

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Author

Keywords

Comments

a(n) = number of Standard Young Tableaux of shape (n+3,4). - David Callan, Aug 17 2004
a(n) = A214292(n+6,3). - Reinhard Zumkeller, Jul 12 2012
a(n) for n > 0 is the number of n-extended coalescent histories for a matching caterpillar gene tree and species tree with 5 leaves. - Noah A Rosenberg, Jun 16 2022

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. 796.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Fifth diagonal of Catalan triangle A033184. Fifth column of Catalan triangle A009766.
Numerator polynomial 14 - 28x + 20x^2 - 5x^3 from fourth row of triangle A062991.

Programs

  • Magma
    [n*(n+5)*(n+6)*(n+7)/24: n in [0..40]]; // Vincenzo Librandi, Mar 20 2013
    
  • Maple
    A005587:=z*(-14+28*z-20*z**2+5*z**3)/(z-1)**5; # Simon Plouffe in his 1992 dissertation
    seq(numbperm(n,4)/24-numbperm(n,3)/6, n=7..46); # Zerinvary Lajos, May 20 2008
    a:=n->(sum(numbcomp(n,4), j=9..n)):seq(a(n)/4, n=8..47); # Zerinvary Lajos, Aug 26 2008
  • Mathematica
    Table[n (n + 5) (n + 6) (n + 7)/24, {n, 0, 60}] (* Vladimir Joseph Stephan Orlovsky, Jun 22 2011 *)
    LinearRecurrence[{5,-10,10,-5,1},{0,14,42,90,165},40] (* Harvey P. Dale, Aug 17 2017 *)
  • PARI
    x='x+O('x^50); concat([0], Vec((14 - 28*x + 20*x^2 - 5*x^3) / (1 - x)^5)) \\ G. C. Greubel, Jul 01 2017

Formula

G.f.: (14 - 28*x + 20*x^2 - 5*x^3) / (1 - x)^5.
a(n) = C(7+n, 4) - C(7+n, 3). - Zerinvary Lajos, Dec 09 2005
E.g.f.: (1/24)*x*(336 + 168*x + 24*x^2 + x^3)*exp(x). - G. C. Greubel, Jul 01 2017
From Amiram Eldar, Jun 28 2022: (Start)
Sum_{n>=1} 1/a(n) = 153/1225.
Sum_{n>=1} (-1)^(n+1)/a(n) = 288*log(2)/35 - 20759/3675. (End)
a(n) = A024191(n+1)-5. - R. J. Mathar, Nov 22 2024

Extensions

M4929 (this sequence) and M4930 were the same.
More terms from Matthew Conroy, Jan 16 2006
Plouffe Maple line edited by N. J. A. Sloane, May 13 2008