Self-convolution of row n of array T given by A026758.

Terms

a(0) =1a(1) =2a(2) =6a(3) =26a(4) =91a(5) =424a(6) =1563a(7) =7490a(8) =28363a(9) =138154a(10) =532277a(11) =2622108a(12) =10229514a(13) =50827494a(14) =200236656a(15) =1001864238a(16) =3978724091a(17) =20024629606a(18) =80072228433a(19) =405071776024