Triangle read by rows: T(n,k) = binomial(k*n,n), 1 <= k <= n.

Terms

a(0) =1a(1) =1a(2) =6a(3) =1a(4) =20a(5) =84a(6) =1a(7) =70a(8) =495a(9) =1820a(10) =1a(11) =252a(12) =3003a(13) =15504a(14) =53130a(15) =1a(16) =924a(17) =18564a(18) =134596a(19) =593775a(20) =1947792a(21) =1a(22) =3432a(23) =116280a(24) =1184040a(25) =6724520a(26) =26978328a(27) =85900584a(28) =1a(29) =12870