OFFSET
0,2
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 (1,1,0,0,-1,0,-1,-1,0,1,1,2,0,0,0,-2,-1,-1,0,1,1,0,1,0,0,-1,-1,1).
FORMULA
G.f.: (1+q)(1+q^2)(1+q^3)(1+q^4)(1+q^5)(1+q^6)(1+q^7)/((1-q)(1-q^2)(1-q^3)(1-q^4)(1-q^5)(1-q^6)(1-q^7)).
a(n) = a(n-1) + a(n-2) - a(n-5) - a(n-7) - a(n-8) + a(n-10) + a(n-11) + 2*a(n-12) - 2*a(n-16) - a(n-17) - a(n-18) + a(n-20) + a(n-21) + a(n-23) - a(n-26) - a(n-27) + a(n-28) for n>28. - Colin Barker, Jan 02 2020
MATHEMATICA
CoefficientList[Series[Times@@(1+x^Range[7])/Times@@(1-x^Range[7]), {x, 0, 40}], x] (* Harvey P. Dale, Aug 30 2017 *)
PROG
(PARI) Vec((1+x)*(1+x^2)*(1+x^3)*(1+x^4)*(1+x^5)*(1+x^6)*(1+x^7) / ((1-x)*(1-x^2)*(1-x^3)*(1-x^4)*(1-x^5)*(1-x^6)*(1-x^7)) + O(x^40)) \\ Colin Barker, Jan 02 2020
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
James A. Sellers, Mar 27 2000
STATUS
approved