Composite numbers k such that both phi(k+12) = phi(k) + 12 and sigma(k+12) = sigma(k) + 12.

A056777

Composite numbers k such that both phi(k+12) = phi(k) + 12 and sigma(k+12) = sigma(k) + 12.

Terms

    a(0) =65a(1) =209a(2) =11009a(3) =38009a(4) =680609a(5) =2205209a(6) =3515609a(7) =4347209a(8) =10595009a(9) =12006209a(10) =31979009a(11) =89019209a(12) =169130009a(13) =244766009a(14) =247590209a(15) =258084209a(16) =325622009a(17) =357777209a(18) =377330609a(19) =441630209a(20) =496175609a(21) =640343009a(22) =1006475609

External references