Numbers k such that (phi(k) + sigma(k))/rad(k)^2 is an integer, that is (phi(k) + sigma(k)) is divisible by every prime factor of k squared.

A121850

Numbers k such that (phi(k) + sigma(k))/rad(k)^2 is an integer, that is (phi(k) + sigma(k)) is divisible by every prime factor of k squared.

Terms

    a(0) =1a(1) =2a(2) =588a(3) =864a(4) =2430a(5) =7776a(6) =27000a(7) =55296a(8) =69984a(9) =82134a(10) =215622a(11) =432000a(12) =497664a(13) =629856a(14) =675000a(15) =862488a(16) =1499136a(17) =1749600a(18) =2187000a(19) =2667168a(20) =3449952a(21) =3538944a(22) =4287500a(23) =4312440a(24) =4478976a(25) =4563000a(26) =5668704a(27) =6912000a(28) =10800000a(29) =13045131

External references