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

Terms

a(0) =-2a(1) =4a(2) =4a(3) =13a(4) =20a(5) =13a(6) =41a(7) =69a(8) =69a(9) =41a(10) =183a(11) =268a(12) =264a(13) =268a(14) =183a(15) =1099a(16) =1405a(17) =1080a(18) =1080a(19) =1405a(20) =1099a(21) =7943a(22) =9486a(23) =5970a(24) =4080a(25) =5970a(26) =9486a(27) =7943a(28) =65547a(29) =75775