### User Tools

To create and edit articles, please register and log-in

### Main Menu : categories & index etc.

Click categories to expand

A-Z listingplugin-autotooltip__plain plugin-autotooltip_bigA-Z listing

This is an alphabetical index of all content pages.

Other categories

Utilities

Also see

Feeds + s.e.o. etc.
sitemap file
A-Z listing (archived)

Indexed under : Mathematics

# Lemoine's conjecture

In 1895, French mathematician รmile Lemoine proposed that :

2n + 1 = p + 2q always has a solution in primes p and q (not necessarily distinct) for n > 2.
[source below]

In plain language :

All odd integers greater than 5 can be represented as the sum of an odd prime number and an even semiprime.
[source below]

e.g.

13=3+(2ร5)
19=5+(2ร7)

Although the conjecture has been computationally checked up to at least 1010, there is currently no proof (or disproof).

Note: The conjecture is also called Levy's Conjecture which was (re)proposed in 1963.

## Dear reader : Do you have any suggestions for the site's content?

Ideas for new topics, and suggested additions / corrections for older ones, are always welcome.

If you have skills or interests in a particular field, and have suggestions for Wikenigma, get in touch !

Or, if you'd like to become a regular contributor . . . request a login password. Registered users can edit the entire content of the site, and also create new pages.

( The 'Notes for contributors' section in the main menu has further information and guidelines etc.)

## Automatic Translation

You are currently viewing an auto-translated version of Wikenigma

Please be aware that no automatic translation engines are 100% accurate, and so the auto-translated content will very probably feature errors and omissions.

Nevertheless, Wikenigma hopes that the translated content will help to attract a wider global audience.

Show another (random) article

Further resources :

### Page Tools

DOKUWIKI IMPLEMENTATION DESIGN BY UNIV.ORG.UK DECEMBER 2023