OFFSET
0,2
REFERENCES
G. Balzarotti and P. P. Lava, Le sequenze di numeri interi, Hoepli, 2008, p. 60.
EXAMPLE
If we rewrite the matrix putting on the top the upper left edge and then we sum the numbers following a boustrophedon path we have:
.........../.1.
........../_____
...........1...1.\
........._________\
......./.1...2...1.
....../______________
.......1...2...1...1.\
....._________________\
.../.1...2...3...2...1.
../_____________________
...1...2...3...1...1...1.
then
1, 1+1, 1+1+1, 1+1+1+1, 1+1+1+1+2, 1+1+1+1+2+1, 1+1+1+1+2+1+1, 1+1+1+1+2+1+1+2, 1+1+1+1+2+1+1+2+1, 1+1+1+1+2+1+1+2+1+1, ...
That is 1, 2, 3, 4, 6, 7, 8, 10, 11, 12, 13, 15, 18, 20, etc.
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paolo P. Lava and Giorgio Balzarotti, May 30 2006
STATUS
approved