a(n) = numerator(Sum_{k=1..n} 1/(prime(k)-1)).

Terms

a(0) =1a(1) =3a(2) =7a(3) =23a(4) =121a(5) =21a(6) =173a(7) =1597a(8) =17927a(9) =127469a(10) =129317a(11) =43619a(12) =44081a(13) =44521a(14) =1033223a(15) =13538159a(16) =395369371a(17) =132680013a(18) =400467919a(19) =402757063a(20) =1214947859a(21) =1221110939a(22) =50305908619a(23) =50529880549a(24) =101470376303a(25) =509322834499