a(n) = a(n-1) + a(n-2) + a([n/2]) + a([n/3]) + ... + a([n/n]), where a(0) = 1, a(1) = 2, a(2) = 3.

Terms

a(0) =1a(1) =2a(2) =3a(3) =9a(4) =19a(5) =37a(6) =74a(7) =131a(8) =238a(9) =410a(10) =710a(11) =1184a(12) =2014a(13) =3320a(14) =5516a(15) =9044a(16) =14888a(17) =24262a(18) =39698a(19) =64510a(20) =105089a(21) =170545a(22) =277057a(23) =449027a(24) =728502a(25) =1179967a(26) =1912216a(27) =3096110a(28) =5014519a(29) =8116824