Column 0 of triangle A107870; a(n) = C( n*(n-1)/2 + n+2, n).

A107871

Column 0 of triangle A107870; a(n) = C( n*(n-1)/2 + n+2, n).

Terms

    a(0) =1a(1) =3a(2) =10a(3) =56a(4) =495a(5) =6188a(6) =100947a(7) =2035800a(8) =48903492a(9) =1362649145a(10) =43183019880

External references