Triangle, read by rows, where T(n,k) = C(n*(n-1)/2 - k*(k-1)/2 + n-k, n-k).

Terms

a(0) =1a(1) =1a(2) =1a(3) =3a(4) =2a(5) =1a(6) =20a(7) =10a(8) =3a(9) =1a(10) =210a(11) =84a(12) =21a(13) =4a(14) =1a(15) =3003a(16) =1001a(17) =220a(18) =36a(19) =5a(20) =1a(21) =54264a(22) =15504a(23) =3060a(24) =455a(25) =55a(26) =6a(27) =1a(28) =1184040a(29) =296010