Sequence associated with a(n) = 2*a(n-1) + k*(k+2)*a(n-2).

Terms

a(0) =1a(1) =3a(2) =12a(3) =40a(4) =120a(5) =336a(6) =896a(7) =2304a(8) =5760a(9) =14080a(10) =33792a(11) =79872a(12) =186368a(13) =430080a(14) =983040a(15) =2228224a(16) =5013504a(17) =11206656a(18) =24903680a(19) =55050240a(20) =121110528a(21) =265289728a(22) =578813952a(23) =1258291200a(24) =2726297600a(25) =5888802816a(26) =12683575296a(27) =27246198784