165297834
domain: N
Appears in sequences
- a(n) = 2*3^n*(2*n)!/(n!*(n+2)!).at n=10A000168
- Expansion of g.f. c(3x)^4, where c(x) is the g.f. of A000108.at n=8A101602
- Triangle T(n,k) read by rows: T(n,k) is the number of rooted genus-k maps with n edges, n>=0, 0<=k<=n.at n=55A238396
- Triangle read by rows: T(n,g) is the number of rooted maps with n edges on an orientable surface of genus g.at n=30A269919