Least number k such that n divides gcd(sigma(k), phi(k), tau(k)).

Terms

a(0) =1a(1) =3a(2) =18a(3) =15a(4) =3344a(5) =45a(6) =24128a(7) =30a(8) =882a(9) =3344a(10) =1012736a(11) =126a(12) =1953792a(13) =24128a(14) =16200a(15) =168a(16) =452263936a(17) =2016a(18) =1852571648a(19) =3344a(20) =40768a(21) =1012736a(22) =27007123456a(23) =420a(24) =1490000a(25) =1953792a(26) =103968a(27) =24128a(29) =30096a(31) =840