[This article was first published on R – TomazTsql, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here)Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.Stanislaw Ulam, Los Alamos, 1963 was bored in a meeting and he started dooddling integers in a spiral and circled the primes. Diagonal lines appeared. He later showed it to Martin Gardner, to Ulam surprise, Gardner published his findings in Scientific American. We are still confused to this day.Ulam prime spiral (or short Ulam spiral) with dimensions of 150 x 150 and total of 2547prime numbers (11.2 % coverage).But Ulam was not doodling some little houses or boats, or cars like a normal person. No. He wrote numbers in a spiral. Then circled all the prime numbers. Then stared at what he had created with the dawning horror of a man who has seen too much.So where does the spiral comes from? Start with 1 in the middle. Write the number in a spiral outward. And then highlight all the prime numbers. If you draw long enough diagonal lines will appear.Primary function has initial position and directions calculated, in order to have the symmetry of the plot.ulam_prime_spiral