Coefficients of Chebyshev T polynomials: a(n) = A053120(n+8, n), n >= 0.

Terms

a(0) =1a(1) =9a(2) =50a(3) =220a(4) =840a(5) =2912a(6) =9408a(7) =28800a(8) =84480a(9) =239360a(10) =658944a(11) =1770496a(12) =4659200a(13) =12042240a(14) =30638080a(15) =76873728a(16) =190513152a(17) =466944000a(18) =1133117440a(19) =2724986880a(20) =6499598336a(21) =15386804224a(22) =36175872000a(23) =84515225600a(24) =196293427200a(25) =453437816832