OFFSET
1,2
COMMENTS
Requiring that the absolute values of the differences in the difference triangle only occur at most once each leads to the Zorach additive triangle. (See A035312.)
EXAMPLE
The triangle begins:
1,
2,3,
4,6,9,
-5,-1,5,14,
13,8,7,12,26,
-30,-17,-9,-2,10,36.
Example:
Considering the rightmost value of the 4th row: Writing a 10 here instead, the first 4 rows of the triangle become:
1
2,3
4,6,9
-9,-5,1,10
But 1 already occurs earlier in the triangle. So 10 is not the rightmost element of row 4.
Checking 11,12,13,14; 14 is the smallest value that can be the rightmost element of row 4 and not have any elements of row 4 occur earlier in the triangle.
CROSSREFS
KEYWORD
sign,tabl
AUTHOR
Leroy Quet, Jan 06 2008
EXTENSIONS
Rows 7-10 from Andrey Zabolotskiy, May 29 2017
STATUS
approved