a(0)=3, a(1)=7; thereafter a(n) = a(n-1) + a(n-2) + 1.

Terms

a(0) =3a(1) =7a(2) =11a(3) =19a(4) =31a(5) =51a(6) =83a(7) =135a(8) =219a(9) =355a(10) =575a(11) =931a(12) =1507a(13) =2439a(14) =3947a(15) =6387a(16) =10335a(17) =16723a(18) =27059a(19) =43783a(20) =70843a(21) =114627a(22) =185471a(23) =300099a(24) =485571a(25) =785671a(26) =1271243a(27) =2056915a(28) =3328159a(29) =5385075