Numbers k such that sigma(k), sigma(k^2) and sigma(k^3) are primes.
A299147
Numbers k such that sigma(k), sigma(k^2) and sigma(k^3) are primes.
Terms
- a(0) =4a(1) =64a(2) =289a(3) =253541929a(4) =499477801a(5) =1260747049a(6) =14450203681a(7) =25391466409a(8) =256221229489a(9) =333456586849a(10) =341122579249a(11) =459926756041a(12) =911087431081a(13) =928731181849
External references
- oeis: A299147