Gpf(n): greatest prime dividing n, for n >= 2; a(1)=1.

Terms

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