A054132 T(2n+1,n), array T as in A054126.

3, 13, 68, 394, 2396, 14925, 94248, 600498, 3851012, 24821845, 160646528, 1043245180, 6794418992, 44360061964, 290244849376

Offset: 0

Author

Clark Kimberling

Keywords

• nonn

Programs

PARI

a(n) = 2^n + sum(m=0, n+1, binomial(3*n+1,m)) \\ Jianing Song, May 30 2022

Formula

a(n) = A052509(4*n+2,3*n+2) + A052509(4*n+2,n+1) = 2^n + Sum_{m=0..n+1} binomial(3*n+1,m). - Jianing Song, May 30 2022