G.f. satisfies: A(x) = exp( Sum_{n>=1} [Sum_{k=0..2*n} A200536(n,k)^2 * x^k] / A(x)^n * x^n/n ), where A200536(n,k) is the coefficient of x^k in (1+3*x+2*x^2)^n.
A200537
G.f. satisfies: A(x) = exp( Sum_{n>=1} [Sum_{k=0..2*n} A200536(n,k)^2 * x^k] / A(x)^n * x^n/n ), where A200536(n,k) is the coefficient of x^k in (1+3*x+2*x^2)^n.
Terms
- a(0) =1a(1) =1a(2) =9a(3) =13a(4) =40a(5) =72a(6) =144a(7) =252a(8) =432a(9) =720a(10) =1152a(11) =1872a(12) =2880a(13) =4608a(14) =6912a(15) =10944a(16) =16128a(17) =25344a(18) =36864a(19) =57600a(20) =82944a(21) =129024a(22) =184320a(23) =285696a(24) =405504a(25) =626688a(26) =884736a(27) =1363968a(28) =1916928a(29) =2949120
External references
- oeis: A200537