a(n) = Sum_{k=1..n} floor(n/prime(k)^2).

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =1a(5) =1a(6) =1a(7) =2a(8) =3a(9) =3a(10) =3a(11) =4a(12) =4a(13) =4a(14) =4a(15) =5a(16) =5a(17) =6a(18) =6a(19) =7a(20) =7a(21) =7a(22) =7a(23) =8a(24) =9a(25) =9a(26) =10a(27) =11a(28) =11a(29) =11