You have to use the TeX file available here. Download gPENv02n1eng.tex. The deadline for your submission is 15th, July..

Before you contact Yimin Ge, please have a look at the PEN Global page at http://projectpen.wordpress.com/global .

Notice: We’ve already find translators: in Vietnamese,  Greek, Spanish, Bangla, Bosnian, Chinese, Croatian, Serbian [Latin] and Serbian [Cyrillic]

Daniel Kohen (Argentina)
Cosmin Pohoata (Romania)
Harun Šiljak (Bosnia and Herzegovina)
Peter Vandendriessche (Belgium)

Anyone who wants to be one of the Editors-in-Chief of the fourth and fifth issue of Problems in Elementary Number Theory (2010), APPLY NOW.

Please, send an email to us at pen@problem-solving.be with your brief C.V.

You need to know basic LaTeX skills and of course you have to be fluent with Olympiad-style problems from Elementary number theory.

We are planning to recruit two or three Editors-in-Chief for Problems in Elementary Number Theory 2010. The deadline for application is 31th, July.

from Hojoo Lee (the founder of project PEN)

This weblication is written by PEN team and contributors:

Alexander Remorov (Canada),
Darij Grinberg (Germany),
Harun Siljak (Bosnia and Herzegovina),
Marin Misur (Croatia).

We also need to thank  two Editors-in-Chief:

Daniel Kohen (Argentina) and Cosmin Pohoata (Romania).

Here goes the table of contents:

If is a natural number, prove that the number

is not a perfect square.

O51 Prove the among consecutive integers it is always possible to find one which is relatively prime to all the rest.

Here is the official solution file: PEN A9 A37 O51

If is a natural number, prove that the number

is not a perfect square.

O51 Prove the among consecutive integers it is always possible to find one which is relatively prime to all the rest.

Here is the official solution file (written by Darij Grinberg, Germany): pen19.pdf.

Here is the official solution file: pen18.pdf

is an integer.

Here is the official solution file: pen17.pdf.