Pairs (j, k) of numbers j<k such that phi(j) = phi(k), sigma(j) = sigma(k), d(j) = d(k).

Terms

a(0) =568a(1) =638a(2) =1704a(3) =1914a(4) =1824a(5) =1836a(6) =2840a(7) =3190a(8) =3051a(9) =3219a(10) =3976a(11) =4466a(12) =4185a(13) =4389a(14) =4960a(15) =5236a(16) =5112a(17) =5742a(18) =6102a(19) =6438a(20) =6368a(21) =6764a(22) =7384a(23) =8294a(24) =7749a(25) =8151a(26) =8370a(27) =8778a(28) =8520a(29) =9570