A Fielder sequence.

Terms

a(0) =1a(1) =3a(2) =4a(3) =11a(4) =21a(5) =36a(6) =64a(7) =115a(8) =211a(9) =383a(10) =694a(11) =1256a(12) =2276a(13) =4126a(14) =7479a(15) =13555a(16) =24566a(17) =44523a(18) =80694a(19) =146251a(20) =265066a(21) =480406a(22) =870689a(23) =1578040a(24) =2860046a(25) =5183558a(26) =9394699a(27) =17026986a(28) =30859771a(29) =55930361