a(n) = Sum_{k=1..n} binomial(floor(n/k)+4,5).

Terms

a(0) =1a(1) =7a(2) =23a(3) =64a(4) =135a(5) =282a(6) =493a(7) =864a(8) =1375a(9) =2166a(10) =3168a(11) =4715a(12) =6536a(13) =9132a(14) =12278a(15) =16525a(16) =21371a(17) =27998a(18) =35314a(19) =44995a(20) =55847a(21) =69504a(22) =84455a(23) =103882a(24) =124428a(25) =150005a(26) =177921a(27) =212017a(28) =247978a(29) =292890