I accidentally created
   [1]https://en.wikipedia.org/wiki/Ulam_spiral in Excel about a
   year and a half ago during my "numbers are the answer" period. I
   was SO EXCITED because these prime numbers were lining up along
   the diagonals! I was telling my smarter friends about my new
   discovery - they were excited... and then... I found this...
   some other guy 50 yrs ago did it already :-| but at least I was
   on the right track.

References

   Visible links
   1. https://en.wikipedia.org/wiki/Ulam_spiral