OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..1000
FORMULA
G.f.: (x^12-x^11+x^10+3*x^9+5*x^8+x^7+4*x^6+x^5+5*x^4+3*x^3+x^2-x+1) / ((x^2+1)*(x^2-x+1)*(x^2+x+1)^3*(x+1)^4*(x-1)^8). - Alois P. Heinz, Apr 21 2015
EXAMPLE
For n = 2, the set {1,1,2,2,3,3} can be partitioned into two sets in four ways: {{112},{233}}, {{113},{223}}, {{122},{133}}, and {{123},{123}}.
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Tatsuru Murai, Jan 27 2015
EXTENSIONS
Fixed definition and examples by Kellen Myers, Apr 21 2015
a(14)-a(39) from Alois P. Heinz, Apr 21 2015
STATUS
approved