a(n) is the least integer k such that there are n values of i <= k for which gpf(i^2 + 1) = gpf(k^2 + 1), where gpf(x) is the greatest prime factor of x.
A258840
a(n) is the least integer k such that there are n values of i <= k for which gpf(i^2 + 1) = gpf(k^2 + 1), where gpf(x) is the greatest prime factor of x.
Terms
- a(0) =1a(1) =3a(2) =7a(3) =38a(4) =47a(5) =157a(6) =302a(7) =327a(8) =515a(9) =616a(10) =697a(11) =798a(12) =818a(13) =1303a(14) =2818a(15) =3141a(16) =3323a(17) =5648a(18) =6962a(19) =9193a(20) =9872a(21) =13213a(22) =13747a(23) =15445a(24) =16271a(25) =17149a(26) =18263a(27) =20491a(28) =20727a(29) =24389
External references
- oeis: A258840