OFFSET
1,2
COMMENTS
All pairs (i,j) having i > j occur except those of the form (i,i-1) for i>=3. (Those are included at A097285.)
EXAMPLE
Terms are lexically ordered in pairs by sum:
1 2 (sum = 3)
1 3 (sum = 4)
1 4 2 3 (two pairs having sum = 5), etc.
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Aug 05 2004
STATUS
approved