Column 1 in the matrix of A279212 (whose indexing starts at 0).

Terms

a(0) =2a(1) =6a(2) =15a(3) =37a(4) =88a(5) =204a(6) =464a(7) =1040a(8) =2304a(9) =5056a(10) =11008a(11) =23808a(12) =51200a(13) =109568a(14) =233472a(15) =495616a(16) =1048576a(17) =2211840a(18) =4653056a(19) =9764864a(20) =20447232a(21) =42729472a(22) =89128960a(23) =185597952a(24) =385875968a(25) =801112064a(26) =1660944384a(27) =3439329280a(28) =7113539584a(29) =14696841216