Number triangle T(n,k)=binomial(2(n+k),4k).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =15a(5) =1a(6) =1a(7) =70a(8) =45a(9) =1a(10) =1a(11) =210a(12) =495a(13) =91a(14) =1a(15) =1a(16) =495a(17) =3003a(18) =1820a(19) =153a(20) =1a(21) =1a(22) =1001a(23) =12870a(24) =18564a(25) =4845a(26) =231a(27) =1a(28) =1a(29) =1820