What is The Number 23?

On the 23rd of Christmas, my true love gave to me: 23 prime rectangles…

I disagree, unless we have a very different definition of the term ‘shape’. There are many shapes that, while regular, do not involve components of equal size and thus might happen to be made up with numbers that are prime. The first one that occurs to me are the shapes of regular hexagons made up out of closely packed circles or miniature hexagons.

Aside from a single element, the next hexagon is made up of seven elements - one in the middle and six surrounding it. Seven is, of course, a prime number. Then the next biggest involves laying twelve further elements in another ‘ring’ outside, six at the points and six more in between the points, for a total of 19 as the third hexagonal number. (Also prime.)

Working out the first 30 hexagonal numbers and doing my best to factor them, I get the following results:


1	Neither
7	Prime
19	Prime
37	Prime
61	Prime
91	7 * 13
127	Prime
169	13 * 13
217	7 * 31
271	Prime
331	Prime
397	Prime
469	7 * 67
547	Prime
631	Prime
721	7 * 103
817	19 * 43
919	Prime
1027	13 * 79
1141	7 * 163
1261	13 * 97
1387	19 * 73
1519	7 * 7 * 31
1657	Prime
1801	Prime
1951	Prime
2107	7 * 7 * 43
2269	Prime
2437	Prime
2611	7 * 373

That’s 16 primes, 13 composites, and 1 neither. Not too bad a record. (Of course, it’s the 1 in the center that keeps the sequence from being always a multiple of six, but that is the way that this particular pattern works.)

:slight_smile:

Is that like… a golf ball or soccer ball? The joining of various shapes to make a whole new overall shape?

I think we were defining shape differently, and I was also making the implicit assumption that every example in the series had to be prime. If not, then you can always find some pleasing arrangement of a large number of individual pieces that can be called a shape.

Otherwise you can do it even in two dimensions just by adding primes.

1
1,2 = 3
1,2,3
1,2,3,5 = 11
1,2,3,5,7
1,2,3,5,7,11 = 29
etc.

I wasn’t meaning to imply that there was any series of shapes that was ALWAYS made up by a prime number. That would pretty much mean it made a prime generation algorithm. :slight_smile:

Craziness

Thee Temple of Psychick Youth says

It seems that a lot of their ideology is based on 23, though…

Genesis P. Orridge was a bit of a kook when he started it…and s/he still is…