Triangle, read by rows, where T(n,k) = C(C(n+2,3) - C(k+2,3), n-k) for n >= k >= 0.

Terms

a(0) =1a(1) =1a(2) =1a(3) =6a(4) =3a(5) =1a(6) =120a(7) =36a(8) =6a(9) =1a(10) =4845a(11) =969a(12) =120a(13) =10a(14) =1a(15) =324632a(16) =46376a(17) =4495a(18) =300a(19) =15a(20) =1a(21) =32468436a(22) =3478761a(23) =270725a(24) =15180a(25) =630a(26) =21a(27) =1a(28) =4529365776a(29) =377447148