Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

Let's say that a positive integer $n$ is a happy mother if $6$ divides $n$ and $(n-1,n+1)$ is a pair of twin primes. Is the difference between two consecutive happy mothers necessarily a happy mother itself?
Thanks in advance.

share|improve this question

2 Answers 2

up vote 4 down vote accepted

No; the numbers $312$ and $348$ are consecutive happy mothers, but their difference $36$ is not.

share|improve this answer

No, $30$ and $6$ are happy mothers, but $24$ is not.

share|improve this answer
But $6$ and $30$ are not consecutive happy mothers, there are $12$ and $18$ between them. –  Sylvain Julien May 17 '14 at 12:17

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.