Numbers k such that phi(2*sigma(k)) = 2*sigma(phi(k)).

Terms

a(0) =2a(1) =4a(2) =16a(3) =18a(4) =64a(5) =100a(6) =450a(7) =516a(8) =1458a(9) =4096a(10) =4624a(11) =13932a(12) =14406a(13) =20124a(14) =21780a(15) =28900a(16) =29262a(17) =29616a(18) =36450a(19) =45996a(20) =62500a(21) =65536a(22) =92778a(23) =95916a(24) =106092a(25) =106308a(26) =114630a(27) =114930a(28) =121872a(29) =125652