Cousin Primes

Jen Binder 06 May 2009 21:12

The post on sexy primes made me turn to the web to see if I could find more kinds of primes!

http://mathworld.wolfram.com/CousinPrimes.html

According to that website, cousin primes are of the form (p, p+4). Some known cousin primes are (3, 7), (7, 11), (13, 17), (19, 23), (37, 41), (43, 47), (67, 71).

Wikipedia says the largest known cousin primes are p = (9771919142 · ((53238 · 7879#)2 - 1) + 2310) · 53238 · 7879#/385 + 1, 7879# is a primorial.

If anyone is like me and doesn't know what a primorial is, you can check out wikipedia, which does a better job of explaining it than I could.

http://en.wikipedia.org/wiki/Primorial