G.f. satisfies: A(x) = Sum_{n>=0} x^n * ( (A(x)^n + A(-x)^n)/2 )^n.
A212961
G.f. satisfies: A(x) = Sum_{n>=0} x^n * ( (A(x)^n + A(-x)^n)/2 )^n.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =7a(5) =26a(6) =88a(7) =389a(8) =1617a(9) =7808a(10) =34783a(11) =184426a(12) =878705a(13) =4960662a(14) =25295649a(15) =152048803a(16) =820978097a(17) =5254469132a(18) =30147771222a(19) =204763245407
External references
- oeis: A212961