Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 4500 articles have referenced us, often saying "we would not have discovered this result without the OEIS".
Table of n, a(n) for n=1..64.
for n>=43 a(n) = 2n-4
(PARI) a(n)=sum(i=1, n, sum(j=1, i, if(sign(1/i+1/j+1/n-1/2)-1, 0, 1)))
Sequence in context: A233774 A175313 A080518 * A168101 A027920 A033438
Adjacent sequences: A078591 A078592 A078593 * A078595 A078596 A078597
Benoit Cloitre, Dec 08 2002