a(n) = A127768(2n+1). A bisection of the row sums of the inverse of number triangle A(n,k) = 1/C(n) if k <= n <= 2k, 0 otherwise, where C(n) = A000108(n).

A127770

a(n) = A127768(2n+1). A bisection of the row sums of the inverse of number triangle A(n,k) = 1/C(n) if k <= n <= 2k, 0 otherwise, where C(n) = A000108(n).

Terms

    a(0) =1a(1) =4a(2) =29a(3) =301a(4) =3441a(5) =42019a(6) =534978a(7) =7020706a(8) =94288121a(9) =1289627931a(10) =17902158534a(11) =251577092029

External references