OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..1000
Wikipedia, Partition of a set
FORMULA
G.f.: -(x^8 +x^6 +3*x^5 +2*x^3 +x^2 -1)/((x+1) *(x^15 +3*x^14 -x^13 +5*x^12 +15*x^11 +14*x^10 +9*x^9 +13*x^8 -17*x^7 -7*x^6 -21*x^5 -3*x^3 -2*x +1)).
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Alois P. Heinz, Sep 16 2016
STATUS
approved