OFFSET
1,1
COMMENTS
Is a(n+1)-a(n) always 1,2 or 3?
EXAMPLE
The first 20 terms of A131389 are
0,1,2,-1,3,4,-2,-3,6,-4,5,7,-5,8,-6,-7,9,10,-8,11.
Positions occupied by negatives are
4,7,8,10,13,15,16,19.
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Apr 03 2010
STATUS
approved