A185413 A000027 written clockwise as spiral and read counterclockwise.

2, 1, 4, 3, 12, 11, 10, 9, 8, 7, 6, 5, 16, 15, 14, 13, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 36, 35, 34, 33, 32, 31, 56, 55, 54, 53, 52, 51, 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 64, 63, 62, 61, 60, 59, 58, 57

Offset: 1

Author

Paul Curtz, Feb 08 2011

Keywords

• nonn
• easy

Comments

A permutation of the natural numbers. Variant of A090861.

Examples

			  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
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..1024
• Index to sequences related to permutations of the integers

Crossrefs

Cf. A185586, A054552.