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A001976 Number of partitions of floor(5n/2)-1 into n nonnegative integers each no more than 5.
(Formerly M2545 N1006)
+0
1
1, 3, 6, 11, 19, 32, 48, 71, 101, 141, 188, 249, 322, 414, 518, 645, 791, 966, 1160, 1389, 1645, 1943, 2268, 2642, 3053, 3521, 4026, 4596, 5214, 5907, 6648, 7473, 8359, 9339, 10380, 11526, 12747, 14085, 15498, 17039, 18671, 20444, 22308, 24326, 26452 (list; graph; listen)
OFFSET

0,2

COMMENT

In Cayley's terminology, this is the number of literal terms of degree n and of weight floor(5n/2)-1 involving the letters a, b, c, d, e, f, having weights 0, 1, 2, 3, 4, 5 respectively. - Herman Jamke (hermanjamke(AT)fastmail.fm), Feb 17 2008

REFERENCES

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

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

A. Cayley, Numerical tables supplementary to second memoir on quantics, Collected Mathematical Papers. Vols. 1-13, Cambridge Univ. Press, London, 1889-1897, Vol. 2, p. 276-281.

LINKS

A. Cayley, Numerical tables supplementary to second memoir on quantics, Collected Mathematical Papers. Vols. 1-13, Cambridge Univ. Press, London, 1889-1897, Vol. 2, p. 276-281.

FORMULA

Coefficient of x^w*z^n in the expansion of 1/((1-z)(1-xz)(1-x^2z)(1-x^3z)(1-x^4z)(1-x^5z)), where w=floor(5n/2)-1. - Herman Jamke (hermanjamke(AT)fastmail.fm), Feb 17 2008

PROGRAM

(PARI) f=1/((1-z)*(1-x*z)*(1-x^2*z)*(1-x^3*z)*(1-x^4*z)*(1-x^5*z)); n=350; p=subst(subst(f, x, x+x*O(x^n)), z, z+z*O(z^n)); for(d=1, 60, w=floor(5*d/2)-1; print1(polcoeff(polcoeff(p, w), d)", ")) - Herman Jamke (hermanjamke(AT)fastmail.fm), Feb 17 2008

CROSSREFS

Cf. A001975.

Sequence in context: A004133 A050228 A114089 this_sequence A144115 A116557 A001911

Adjacent sequences: A001973 A001974 A001975 this_sequence A001977 A001978 A001979

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

Better definition and more terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Feb 17 2008

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.


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