Self-convolution of row n of array T given by A026022.

Terms

a(0) =1a(1) =2a(2) =6a(3) =20a(4) =56a(5) =208a(6) =493a(7) =1974a(8) =4336a(9) =18258a(10) =38380a(11) =167464a(12) =342056a(13) =1532376a(14) =3067156a(15) =14022168a(16) =27646080a(17) =128438893a(18) =250291902a(19) =1178090212a(20) =2274524200a(21) =10822168448a(22) =20736353110a(23) =99564168884a(24) =189575748320a(25) =917316990660