OFFSET
1,1
COMMENTS
Any offset (x,y) in this spiral is a permutation of the natural numbers.
LINKS
EXAMPLE
For example, if the spiral is oriented such that 1 is immediately to the left of 2, as shown below, then a(1) = 6 because 6 is immediately to the left of 1.
21--22--23--24--25--26
| |
20 7---8---9---10 27
| | | |
19 6 1---2 11 28
| | | | |
18 5---4---3 12 29
| | |
17--16--15--14--13 30
|
36--35--34--33--32--31
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Frank Ellermann, Feb 22 2002
STATUS
approved