A Catalan transform of Pell(n+1).

Terms

a(0) =1a(1) =2a(2) =7a(3) =26a(4) =100a(5) =392a(6) =1555a(7) =6218a(8) =25006a(9) =100988a(10) =409162a(11) =1661948a(12) =6764194a(13) =27575732a(14) =112570675a(15) =460058906a(16) =1881978694a(17) =7704907724a(18) =31566153058a(19) =129400608044a(20) =530734613920