What pattern/what symmetry?  Look................


20 - 30.............eliminate just the even numbers and anything ending in 5.........this is true for any consecutive 10 number............


1, 3, 7, 9.............are evenly spaced............like two sets of snake eyes.............................



so........in 20 - 30...........for example......................20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30...........................


                       20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30

Or looked at another way............no number, in a consecutive 10 number sequence................can end in 0, 2, 4, 5, 6, 8, 0...............................the two ends cannot be.............the middle number.........5 cannot be...........the the on the bottom.............2 and 4 cannot be.........neither can 6 or 8............any number higher than 10 ending in those can ever be prime................anything that ends with a 5 is divisible by 5..........any even number cannot be prime...........





The Greeks and modern mathematicians both note that primes are irregularly spaced from each other............


oddly enough...................doing what i did.......my convoluted logic........a pattern emerges.........


take..............20 - 30..................b/c    1, 3, 7, 9 have a symmetry.................i don't know the math Reiman was applying.........but he found a pattern...........about a line..........



The ancient Greeks proved (ca 300 BC) that there were infinitely many primes and that they were irregularly spaced (there can be arbitrarily large gaps between successive primes).  On the other hand, in the nineteenth century it was shown that the number of primes less than or equal to n approaches n/(log n) (as n gets very large); so a rough estimate for the nth prime is n log n (see the document "How many primes are there?")