1320064

Appears in sequences

• Number of series-parallel networks with n labeled edges. Also called yoke-chains by Cayley and MacMahon.at n=7A006351
• Triangle of series-parallel numbers.at n=43A036654
• Triangle of series-parallel numbers.at n=44A036654
• Triangle T(n,k) read by rows: coefficients of polynomials P_n(t) defined in Formula section.at n=35A278458
• Array read by downward antidiagonals: A(n,k) = A(n-1,k+1) + 2*(k+1)!*Sum_{j=0..k} A(n-1,j)/j! with A(0,k) = 2*(k+1)!, n >= 0, k >= 0.at n=27A379459
• Array read by downward antidiagonals: A(n,k) = A(n,k-1) + (k+1)*(A(n-1,k) + A(n-1,k+1)) with A(n,0) = A(n-1,0) + A(n-1,1), A(0,k) = 1, n >= 0, k >= 0.at n=35A379460