Smallest k for which the number of divisors d of k such that d == -d^k (mod k) is equal to n, or -1 if no such k exists.

A386913

Smallest k for which the number of divisors d of k such that d == -d^k (mod k) is equal to n, or -1 if no such k exists.

Terms

    a(0) =1a(1) =2a(2) =6a(3) =42a(4) =66a(5) =1770a(6) =2926a(7) =8646a(8) =178486a(9) =90706a(10) =639730a(11) =17646706a(12) =5533066a(13) =35193246a(14) =13775230a(15) =144313246

External references