Partial sums of (A006899, prefixed by a 1).

Terms

a(0) =1a(1) =2a(2) =4a(3) =7a(4) =11a(5) =19a(6) =28a(7) =44a(8) =71a(9) =103a(10) =167a(11) =248a(12) =376a(13) =619a(14) =875a(15) =1387a(16) =2116a(17) =3140a(18) =5188a(19) =7375a(20) =11471a(21) =18032a(22) =26224a(23) =42608a(24) =62291a(25) =95059a(26) =154108a(27) =219644a(28) =350716a(29) =527863