G.f. A(x) satisfies 3*x = Sum_{n=-oo..+oo} (-1)^n * x^(3*n) * (A(x) + x^n)^(3*n) with A(0) = 1.
A380682
G.f. A(x) satisfies 3*x = Sum_{n=-oo..+oo} (-1)^n * x^(3*n) * (A(x) + x^n)^(3*n) with A(0) = 1.
Terms
- a(0) =1a(1) =2a(2) =5a(3) =16a(4) =61a(5) =249a(6) =1052a(7) =4563a(8) =20235a(9) =91420a(10) =419423a(11) =1948712a(12) =9149749a(13) =43345282a(14) =206922865a(15) =994442783a(16) =4807332168a(17) =23360888569a(18) =114048745449a(19) =559114028719
External references
- oeis: A380682