Triangle read by rows: binomial(n,k)*(2*n-k)!, n>=0, 0<=k<=n.

Terms

a(0) =1a(1) =2a(2) =1a(3) =24a(4) =12a(5) =2a(6) =720a(7) =360a(8) =72a(9) =6a(10) =40320a(11) =20160a(12) =4320a(13) =480a(14) =24a(15) =3628800a(16) =1814400a(17) =403200a(18) =50400a(19) =3600a(20) =120a(21) =479001600a(22) =239500800a(23) =54432000a(24) =7257600a(25) =604800a(26) =30240a(27) =720a(28) =87178291200a(29) =43589145600