A068225 Neighbor in 1-2 direction of numbers arranged as clockwise spiral.

2, 11, 12, 3, 4, 1, 8, 9, 10, 27, 28, 29, 30, 13, 14, 15, 16, 5, 6, 7, 22, 23, 24, 25, 26, 51, 52, 53, 54, 55, 56, 31, 32, 33, 34, 35, 36, 17, 18, 19, 20, 21, 44, 45, 46, 47, 48, 49, 50, 83, 84, 85, 86, 87, 88, 89, 90, 57, 58, 59, 60, 61, 62, 63, 64, 37, 38, 39, 40, 41, 42, 43

Offset

1,1

Links

Peter Kagey, Table of n, a(n) for n = 1..10000

Frank Ellermann, Some EIS sequences based on a spiral of natural numbers.

Index entries for sequences that are permutations of the natural numbers.

Example

For example, if the spiral is oriented such that 1 is immediately to the right of 2, as shown below, then a(2) = 11 because 11 is immediately to the right of 2.
  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

Cf. A068226 (inverse, left), A334751 (above), A334752 (below).

Cf. A054552 (middle row right), A054567 (middle row left).

Sequence in context: A153706 A201187 A359207 * A367810 A043080 A108199

Adjacent sequences: A068222 A068223 A068224 * A068226 A068227 A068228

Keyword

nonn,easy

Author

Frank Ellermann, Feb 22 2002

Status

approved