a(n) = a(n-1)*(2n-1) + 2n with a(0)=0.

A093303

a(n) = a(n-1)*(2n-1) + 2n with a(0)=0.

Terms

    a(0) =0a(1) =2a(2) =10a(3) =56a(4) =400a(5) =3610a(6) =39722a(7) =516400a(8) =7746016a(9) =131682290a(10) =2501963530a(11) =52541234152

External references