a(n) = the sum of the terms in the n-th antidiagonal of A124975.

A124014

a(n) = the sum of the terms in the n-th antidiagonal of A124975.

Terms

    a(0) =1a(1) =2a(2) =4a(3) =8a(4) =22a(5) =138a(6) =4952a(7) =7139100

External references