a(n+2) = 5a(n+1) - 3a(n) (n >= 1); a(0) = 1, a(1) = 2, a(2) = 9.

Terms

a(0) =1a(1) =2a(2) =9a(3) =39a(4) =168a(5) =723a(6) =3111a(7) =13386a(8) =57597a(9) =247827a(10) =1066344a(11) =4588239a(12) =19742163a(13) =84946098a(14) =365504001a(15) =1572681711a(16) =6766896552a(17) =29116437627a(18) =125281498479a(19) =539058179514