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A230562
Smallest number that is the sum of 2 positive 4th powers in >= n ways.
5
0, 2, 635318657
OFFSET
0,2
COMMENTS
Hardy and Wright say that a(3) is unknown.
Guy, 2004: "Euler knew that 635318657 = 133^4 + 134^4 = 59^4 + 158^4, and Leech showed this to be the smallest example. No one knows of three such equal sums."
REFERENCES
R. K. Guy, Unsolved Problems in Number Theory, 3rd edition, Springer, 2004, D1
G. H. Hardy and E. M. Wright, An Introduction to the Theory of Numbers, 6th edition, 2008; section 21.11.
EXAMPLE
0 = (empty sum).
2 = 1^4 + 1^4.
635318657 = 59^4 + 158^4 = 133^4 + 134^4.
KEYWORD
hard,more,nonn
AUTHOR
Jonathan Sondow, Oct 25 2013
STATUS
approved