G.f.: exp( Sum_{n>=1} (x^n/n)*[Sum_{k=0..[n/2]} A034807(n,k)^3] ), where A034807 is a triangle of Lucas polynomials.
A171185
G.f.: exp( Sum_{n>=1} (x^n/n)*[Sum_{k=0..[n/2]} A034807(n,k)^3] ), where A034807 is a triangle of Lucas polynomials.
Terms
- a(0) =1a(1) =1a(2) =5a(3) =14a(4) =40a(5) =126a(6) =408a(7) =1332a(8) =4473a(9) =15377a(10) =53627a(11) =189724a(12) =680475a(13) =2467975a(14) =9038578a(15) =33399571a(16) =124400702a(17) =466619283a(18) =1761467038a(19) =6688059913a(20) =25527326897a(21) =97901917060a(22) =377123873505
External references
- oeis: A171185