G.f.: A(x) = F(x*F(x)) where F(x) = 1 + x*F(x)^3 is the g.f. of A001764.
A153291
G.f.: A(x) = F(x*F(x)) where F(x) = 1 + x*F(x)^3 is the g.f. of A001764.
Terms
- a(0) =1a(1) =1a(2) =4a(3) =21a(4) =124a(5) =782a(6) =5145a(7) =34873a(8) =241682a(9) =1704240a(10) =12186900a(11) =88162753a(12) =644058237a(13) =4744733614a(14) =35210349041a(15) =262976828766
External references
- oeis: A153291