a(n) = smallest number k such that Product_{i=2..k+1} prime(i)/(prime(i)-1) > n.
A005580
a(n) = smallest number k such that Product_{i=2..k+1} prime(i)/(prime(i)-1) > n.
Terms
- a(0) =0a(1) =1a(2) =3a(3) =8a(4) =21a(5) =54a(6) =141a(7) =372a(8) =995a(9) =2697a(10) =7397a(11) =20502a(12) =57347a(13) =161658a(14) =458788a(15) =1309626a(16) =3757383a(17) =10828011a(18) =31326513a(19) =90945528
External references
- oeis: A005580