MathDB

1

Part of 2006 Greece JBMO TST

Problems(1)

arranging no around a circle such 2 neighbours of 1,2,..,13 have prime sum

Source: Greece JBMO TST 2006 p1

6/16/2019
a) Is it possible to arrange numbers 1,2,...,131,2,...,13 in a circumference such that the sum of any two neighbouring numbers to be a prime number? b) Is the same problem possible for the numbers 1,2,...,161,2,...,16?
number theoryprime numbersCircular arrayprime