Numbers k such that Sum_{d divides k} sigma(d)/phi(d) is an integer.

Terms

a(0) =1a(1) =2a(2) =3a(3) =6a(4) =10a(5) =21a(6) =30a(7) =42a(8) =78a(9) =110a(10) =210a(11) =330a(12) =390a(13) =930a(14) =1218a(15) =1830a(16) =2025a(17) =2310a(18) =2530a(19) =4050a(20) =4134a(21) =4290a(22) =6090a(23) =7590a(24) =14175a(25) =14910a(26) =22110a(27) =28350a(28) =51090a(29) =52650