A321775 Number of compositions of n into parts with distinct multiplicities and with exactly five parts.
1, 5, 15, 15, 20, 6, 30, 20, 35, 35, 21, 35, 50, 40, 50, 36, 55, 55, 65, 55, 56, 70, 70, 70, 85, 61, 85, 85, 90, 90, 86, 90, 105, 105, 105, 91, 120, 110, 120, 120, 111, 125, 135, 125, 140, 126, 140, 140, 155, 145, 141, 155, 160, 160, 170, 146, 175, 175, 175
Offset: 5
Keywords
Links
- Alois P. Heinz, Table of n, a(n) for n = 5..1000
Crossrefs
Column k=5 of A242887.
Formula
Conjectures from Colin Barker, Dec 11 2018: (Start)
G.f.: x^5*(1 + 6*x + 21*x^2 + 35*x^3 + 49*x^4 + 34*x^5 + 29*x^6) / ((1 - x)^2*(1 + x)*(1 + x^2)*(1 + x + x^2)*(1 + x + x^2 + x^3 + x^4)).
a(n) = -a(n-1) - a(n-2) + a(n-4) + 2*a(n-5) + 2*a(n-6) + a(n-7) - a(n-9) - a(n-10) - a(n-11) for n>15.
(End)