The second right hand column of triangle A167557.

A167558

The second right hand column of triangle A167557.

Terms

    a(0) =1a(1) =12a(2) =160a(3) =2688a(4) =55296a(5) =1351680a(6) =38338560a(7) =1238630400a(8) =44920995840

External references