a(n) = Sum_{k=0..8} binomial(n,k).

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =16a(5) =32a(6) =64a(7) =128a(8) =256a(9) =511a(10) =1013a(11) =1981a(12) =3797a(13) =7099a(14) =12911a(15) =22819a(16) =39203a(17) =65536a(18) =106762a(19) =169766a(20) =263950a(21) =401930a(22) =600370a(23) =880970a(24) =1271626a(25) =1807781a(26) =2533987a(27) =3505699a(28) =4791323a(29) =6474541