A001976 - OEIS

A001976

Number of partitions of floor(5n/2)-1 into n nonnegative integers each no more than 5.
(Formerly M2545 N1006)

0, 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, 28746

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OFFSET

0,3

COMMENTS

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

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

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

Alois P. Heinz, Table of n, a(n) for n = 0..1000

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

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

Index entries for linear recurrences with constant coefficients, signature (2, -1, 0, 1, -2, 2, -2, 2, -2, 0, 2, -2, 2, -2, 2, -1, 0, 1, -2, 1).

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

G.f.: -(x^12 +x^11 +x^10 +2*x^9 +2*x^8 +4*x^7 +x^6 +4*x^5 +2*x^4 +2*x^3 +x^2 +x+1)*x / ((x^4+1) *(x^2+x+1) *(x^2-x+1) *(x^2+1)^2 *(x+1)^3 *(x-1)^5). - Alois P. Heinz, Jul 25 2015

PROG

(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=0, 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: A344003 A050228 A114089 * A144115 A183088 A326957

Adjacent sequences: A001973 A001974 A001975 * A001977 A001978 A001979

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

EXTENSIONS

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

a(0)=0 inserted by Alois P. Heinz, Jul 25 2015

STATUS

approved