I was recently blessed to spend a girls weekend with my adult daughter. While driving to brunch we were talking about our fitness levels and I remarked that mine had changed dramatically over the last 15 years. 315 more words

## Tags » Primes

#### Numbers as products of primes (a useful calculation practice). And the general beauty of primes.

Simon spent hours calculating – something he’s not particularly fond of if it were simple/ pointless sums, the way schoolkids work. His was not pointless! He did it with the solemn purpose of expressing natural numbers as products of primes, the atoms of all numbers. 38 more words

#### Doing Mod N Via Mod R

* Variations on Montgomery’s trick *

Peter Montgomery is a cryptographer at Microsoft. Just recently, Joppe Bos and Arjen Lenstra have edited a book titled *Topics in Computational Number Theory Inspired by Peter L.* 1,314 more words

#### Primes & Factors II

def output_prime_factors(x): x = round(x) x = int(x) i = 0 while i= 2: a=int(x) if a==x: for y in range(2,a): if not ( a % y ): return False else: return False return True return False def get_nth_prime(x): count = 0 num = 0 if type(x) == (float): return None while count != x: if is_prime(num): count = count + 1 num = num + 1 if count == float: return None if count == x: return num - 1 if __name__ == '__main__': output_prime_factors(23) print get_nth_prime(4)

#### Sums of Small Divisors

**— PROBLEM STATEMENT —**

The following problem originates (as far as I can tell) with Douglas Iannucci and was relayed to me via Brian Freidin… 1,243 more words

#### Prime Number Problem

Following is a problem about prime factorization of the sum of consecutive odd primes. (source: problem 80 from The Green Book of Mathematical Problems) 211 more words

#### Fast and slow machines

In my previous post, I presented three hypothetical *machines* which take a positive integer as input and give us something else as output: