G.f.: exp( Sum_{n>=1} A002426(n)/2 * A002426(n) * x^n/n ), where A002426 is the central binomial coefficients and A002426 is the central trinomial coefficients.
A216586
G.f.: exp( Sum_{n>=1} A002426(n)/2 * A002426(n) * x^n/n ), where A002426 is the central binomial coefficients and A002426 is the central trinomial coefficients.
Terms
- a(0) =1a(1) =1a(2) =5a(3) =28a(4) =202a(5) =1579a(6) =13375a(7) =118858a(8) =1098458a(9) =10453452a(10) =101872926a(11) =1012109860a(12) =10218226307a(13) =104570617520
External references
- oeis: A216586