OFFSET
1,2
COMMENTS
In general, let w(i,j) be the weight of the unit square labeled by its
northeast vertex (i,j) and for each (m,n), define
S(m,n)=SUM{SUM{w(i,j), i=1,2,...,m, j=1,2,...,n}.
Then S(m,n) is the weight of the rectangle [0,m]x[0,n]. We call W the weight
array of S and we call S the accumulation array of W. For the case at hand, S is
the array of natural numbers having the following antidiagonals:
(1), then (3,2), then (6,5,4), then (10,9,8,7) and so on.
EXAMPLE
S(2,4)=1+1+2+3+2+1+1+1=14.
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Clark Kimberling, Sep 11 2008
STATUS
approved