Catalan transform of the Pell sequence.

Terms

a(0) =0a(1) =1a(2) =3a(3) =11a(4) =42a(5) =164a(6) =649a(7) =2591a(8) =10408a(9) =41998a(10) =170050a(11) =690370a(12) =2808714a(13) =11446642a(14) =46715469a(15) =190876527a(16) =780679200a(17) =3195628806a(18) =13090353594a(19) =53655587034a(20) =220045073988a(21) =902842397664