Partial sums of A000285.

Terms

a(0) =1a(1) =5a(2) =10a(3) =19a(4) =33a(5) =56a(6) =93a(7) =153a(8) =250a(9) =407a(10) =661a(11) =1072a(12) =1737a(13) =2813a(14) =4554a(15) =7371a(16) =11929a(17) =19304a(18) =31237a(19) =50545a(20) =81786a(21) =132335a(22) =214125a(23) =346464a(24) =560593a(25) =907061a(26) =1467658a(27) =2374723a(28) =3842385a(29) =6217112