[seqfan] Re: Variation on an infinite Sudoku-type array

Zak Seidov zakseidov at mail.ru
Sun Jul 3 01:30:53 CEST 2016

```Dear Kerry,
This is exactly my "old spiral",
see my post to [seqfan] 30 june, 14:05 .
Apparently nobody noticed it in the "hectic" thread
"Sudoku-type array":(

Zak
PS But you've calculated great figures!
While I just mentioned the "idea".
Congrats!

>Суббота,  2 июля 2016, 22:36 +03:00 от Kerry Mitchell <lkmitch at gmail.com>:
>
>Hi all,
>
>This is a spinoff from the "A269526, an infinite Sudoku-type array" thread.
>
>I was intrigued by the idea in the original thread and wanted to try some
>variations.  I didn't like the antidiagonals approach because of the break
>at the end of a line, jumping down to the next line.  So I tried with a
>square spiral (ala Ulam spiral), so that each newly populated cell is
>adjacent to the previous cell.  Here are the central 121 cells:
>
>09  16  02  04  07  14  11  12  01  05  08
>17  08  15  14  13  12  09  10  06  07  03
>01  02  04  11  10  03  08  07  09  13  15
>08  09  07  03  05  06  01  02  04  12  11
>11  12  08  01  02  04  03  06  05  10  14
>15  07  06  05  03  01  02  04  08  11  12
>14  10  03  02  04  05  06  01  07  09  13
>07  11  09  06  01  02  04  05  03  08  10
>04  13  05  07  08  09  10  11  12  06  01
>12  14  10  09  06  13  05  03  15  16  07
>10  15  01  12  16  08  14  13  11  18  17
>
>The sequence begins with "01" in the center.  Here's a list of those
>values, in order:
>
>1
>2
>3
>4
>2
>3
>4
>5
>6
>1
>4
>6
>2
>1
>6
>5
>3
>1
>5
>2
>6
>1
>2
>4
>5
>3
>7
>8
>5
>4
>9
>7
>8
>3
>10
>11
>4
>7
>8
>6
>3
>9
>5
>7
>8
>9
>10
>11
>12
>6
>8
>9
>11
>10
>12
>13
>7
>6
>10
>9
>12
>13
>14
>15
>8
>2
>9
>12
>7
>10
>11
>13
>14
>10
>9
>6
>13
>5
>3
>15
>16
>7
>1
>10
>13
>12
>14
>11
>15
>3
>8
>5
>1
>12
>11
>14
>7
>4
>2
>16
>9
>17
>1
>8
>11
>15
>14
>7
>4
>12
>10
>15
>1
>12
>16
>8
>14
>13
>11
>18
>17
>
>And here are a couple of images of the sequence.  In the first, the colors
>represent the values, from black (small) to white (large).  In the second,
>values <= 100 are black and those > 100 are white.
>
>http://www.kerrymitchellart.com/temp/spiral-low.jpg
>http://www.kerrymitchellart.com/temp/spiral-high.jpg
>
>Kerry
>
>--
>Seqfan Mailing list -  http://list.seqfan.eu/

```