A053798 Number of basis partitions of n+16 with Durfee square size 4.

1, 2, 4, 8, 14, 22, 34, 50, 70, 96, 128, 166, 212, 266, 328, 400, 482, 574, 678, 794, 922, 1064, 1220, 1390, 1576, 1778, 1996, 2232, 2486, 2758, 3050, 3362, 3694, 4048, 4424, 4822, 5244, 5690, 6160, 6656, 7178, 7726, 8302, 8906, 9538, 10200, 10892, 11614

Offset: 0

Author

James Sellers, Mar 27 2000

Keywords

• easy
• nonn

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..10000
• M. D. Hirschhorn, Basis partitions and Rogers-Ramanujan partitions, Discrete Math. 205 (1999), 241-243.
• Index entries for linear recurrences with constant coefficients, signature (3,-3,2,-3,3,-1)

Programs

Mathematica

LinearRecurrence[{3,-3,2,-3,3,-1},{1,2,4,8,14,22,34},50] (* Harvey P. Dale, Dec 29 2019 *)

Formula

G.f.: (1+q)(1+q^2)(1+q^3)(1+q^4)/((1-q)(1-q^2)(1-q^3)(1-q^4)).

a(n) = (n*(n^2+15)+2*A049347(n-1))/9, n>0. G.f. 1+ 2*x*(1-x+x^2-x^3+x^4) / ( (1+x+x^2)*(x-1)^4 ). - R. J. Mathar, Mar 24 2011