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.

A002463 Coefficients of Legendre polynomials.

Original entry on oeis.org

1, 3, 30, 175, 4410, 29106, 396396, 2760615, 156434850, 1122854590, 16291599324, 119224885962, 3515605611700, 26077294372500, 388924218927000, 2913690606794775, 350671234206006450, 2647224022927695750, 40095381399899017500, 304513870316075169750
Offset: 1

Views

Author

Keywords

Comments

Apparently, a(n) divides A000894(n). - Ralf Stephan, Aug 05 2004
Coefficients of cos(x) term of the Tisserand functions of odd order for the planar case with the denominators factored out (see Table 1 from Laskar & Boué's paper) (cf A002462). - Michel Marcus, May 29 2013
Also cos(x) term of the Legendre polynomials of odd order when they are expressed in terms of the cosine function (see 22.3.13 from Abramowitz & Stegun) with the denominators factored out. - Michel Marcus, May 29 2013

References

  • A. Fletcher, J. C. P. Miller, L. Rosenhead and L. J. Comrie, An Index of Mathematical Tables. Vols. 1 and 2, 2nd ed., Blackwell, Oxford and Addison-Wesley, Reading, MA, 1962, Vol. 1, p. 362.
  • G. Prévost, Tables de Fonctions Sphériques. Gauthier-Villars, Paris, 1933, pp. 156-157.
  • 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).

Programs

  • PARI
    lista(nn) = {forstep (n=1, nn, 2, lcmc = 1; for (m=0, n\2, lcmc = lcm(lcmc, denominator(binomial(2*n-2*m, n-m) * binomial(2*m, m)/4^n));); m = n\2; print1(lcmc*binomial(2*n-2*m, n-m) * binomial(2*m, m)/4^n, ", "););} \\ Michel Marcus, May 29 2013
    
  • Python
    from sympy import binomial as C, lcm
    def a_list(nn):
        l = []
        for n in range(1, nn + 1, 2):
            lcmc = 1
            for m in range(n//2 + 1):
                lcmc = lcm(lcmc, (C(2*n - 2*m, n - m)*C(2*m, m)/4**n).denominator)
            m = n//2
            l.append(lcmc*C(2*n - 2*m, n - m)*C(2*m, m)//4**n)
        return l # Indranil Ghosh, Jul 02 2017, after PARI code by Michel Marcus

Extensions

More terms from Michel Marcus, May 29 2013