Subsequence of A014217 (n=2,3,5,6,8,9,11,12,...).

Terms

a(0) =2a(1) =4a(2) =11a(3) =17a(4) =46a(5) =76a(6) =199a(7) =321a(8) =842a(9) =1364a(10) =3571a(11) =5777a(12) =15126a(13) =24476a(14) =64079a(15) =103681a(16) =271442a(17) =439204a(18) =1149851a(19) =1860497a(20) =4870846a(21) =7881196a(22) =20633239a(23) =33385282a(24) =87403803a(25) =141422324a(26) =370248451a(27) =599074578