A108705 Numbers n such that a^n + b^n + c^n + ... is a square, where a*b*c* ... is the prime factorization of n.

1, 2, 16, 27, 512, 3125, 65536, 531441

Offset

1,2

Comments

No more terms through 630000. - Ryan Propper, May 12 2006

Links

Table of n, a(n) for n=1..8.

Example

16 is in the sequence because 16 = 2^4 and 2^16 + 2^16 + 2^16 + 2^16 = 262144
= 512^2.

Crossrefs

Cf. A082872.

Sequence in context: A190046 A067566 A067555 * A113933 A127871 A242933

Adjacent sequences: A108702 A108703 A108704 * A108706 A108707 A108708

Keyword

hard,nonn

Author

Jason Earls, Jun 20 2005

Extensions

Two more terms from Ryan Propper, May 12 2006

Status

approved