Main diagonal of triangle A132784.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =7a(6) =40a(7) =342a(8) =4118a(9) =66581a(10) =1393998a(11) =36722251a(12) =1189340060a(13) =46466456210