Dreamshire | Prime Numbers

Prime Numbers

This tag is associated with 19 posts

By Mike ⋅ June 16, 2009 ⋅ One comment

Investigating which primes will never divide a repunit containing 10**n digits.

By Mike ⋅ June 15, 2009 ⋅ 4 comments

Determining the first forty prime factors of a very large repunit.

By Mike ⋅ June 15, 2009 ⋅ Post a comment

Finding composite values, n, for which n−1 is divisible by the length of the smallest repunits that divide it.

By Mike ⋅ June 15, 2009 ⋅ One comment

Investigating minimal repunits that divide by n.

By Mike ⋅ June 8, 2009 ⋅ Post a comment

What is the first value which can be written as the sum of primes in over five thousand different ways?

By Mike ⋅ June 5, 2009 ⋅ Post a comment

Find arithmetic sequences, made of prime terms, whose four digits are permutations of each other.

By Mike ⋅ May 28, 2009 ⋅ Post a comment

What is the smallest odd composite that cannot be written as the sum of a prime and twice a square?

By Mike ⋅ May 27, 2009 ⋅ Post a comment

Find the smallest prime which, by changing the same part of the number, can form eight different primes.

By Mike ⋅ May 19, 2009 ⋅ 2 comments

What is the value of the first triangle number to have over five hundred divisors?

By Mike ⋅ May 17, 2009 ⋅ 2 comments

Find the largest prime factor of a composite number.