OFFSET
1,1
COMMENTS
The computations were provided by Robert Israel from sci.math. He found no n that had three representations up to k < 10^6. It would be a challenge to find an n with three representations.
LINKS
EXAMPLE
For 36, sum of the coprimes of 9 is 27, add to 9 to get 36; the sum of the coprimes of 12 is 24, add 12 to 24 to also get 36. The corresponding {a,b} for each term is listed at the sci.math reference.
CROSSREFS
KEYWORD
nonn
AUTHOR
J. M. Bergot, Feb 17 2011
EXTENSIONS
a(11)-a(15) from Donovan Johnson, Feb 21 2011
STATUS
approved