Go Back > New To GIMPS? Start Here! > Homework Help

Thread Tools
Old 2021-08-26, 15:54   #12
Dr Sardonicus
Dr Sardonicus's Avatar
Feb 2017

137816 Posts

Originally Posted by bur View Post
Let p and p^2+8 be prime. Prove that p^3+4 is also prime.

So only if p=3 we can have both p and p^2+8 be prime.
Or is it really just about showing that it only holds for p=3 and since 3^3+4=31 is prime, that's the proof?

Last fiddled with by Dr Sardonicus on 2021-08-26 at 15:56
Dr Sardonicus is offline   Reply With Quote

Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
k*b^n+/-c where b is an integer greater than 2 and c is an integer from 1 to b-1 jasong Miscellaneous Math 5 2016-04-24 03:40
Sum of reciprocals of prime k-tuplets mart_r Math 10 2009-04-05 07:29
Always an integer. mfgoode Puzzles 18 2007-07-13 18:03
Sum of all integer digits of all primes between 1 an n AntonVrba Math 2 2006-09-20 17:20
Primes for a mersenne integer DWT FNT gbvalor Math 1 2003-09-08 16:05

All times are UTC. The time now is 14:49.

Wed Oct 20 14:49:25 UTC 2021 up 89 days, 9:18, 0 users, load averages: 0.72, 1.01, 1.12

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.