a(n) = Sum_{k=0..6} binomial(n,k).

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =16a(5) =32a(6) =64a(7) =127a(8) =247a(9) =466a(10) =848a(11) =1486a(12) =2510a(13) =4096a(14) =6476a(15) =9949a(16) =14893a(17) =21778a(18) =31180a(19) =43796a(20) =60460a(21) =82160a(22) =110056a(23) =145499a(24) =190051a(25) =245506a(26) =313912a(27) =397594a(28) =499178a(29) =621616