The (double) Primorial sieve  &  Prime spirals E-mail

Primorial sieve:

en.wikipedia.org: Wheel factorization
www.primesdemystified.com: The Prime Spiral Sieve
www.g-gloeggler.de: Primes and an algorithm for computing prime factors

Last Digit gap of Prime Numbers:

www.nature.com/news: Peculiar pattern found in ‘random’ prime numbers
Youtube: Last Digit of Prime Numbers: The Last Digit of Prime Numbers - Numberphile

Ulam spiral:

en.wikipedia.org: Ulam spiral
Ulamspiral.com: A visual analysis of prime number distribution
Youtube: Prime Spirals: Prime Spirals - Numberphile
Youtube: 41 and more Ulam's Spiral: 41 and more Ulam's Spiral - Numberphile


Miscellaneous: Links