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A108705 Numbers n such that a^n + b^n + c^n + ... is a square, where a*b*c* ... is the prime factorization of n. 0
1, 2, 16, 27, 512, 3125, 65536, 531441 (list; graph; refs; listen; history; text; internal format)
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

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Last modified June 13 00:57 EDT 2021. Contains 344980 sequences. (Running on oeis4.)