[ May 30, 2005 ]
An amazing Palindromic Circle
Giovanni Resta (email)

While Giovanni was solving Rivera's Puzzle 311
he also solved this problem that may interest us.

Which is the minimal non-trivial N such that the numbers
from 1 to N can be disposed in a circle in such a way that
every couple of adjacent numbers has a palindromic sum ?

According to his computations, such number is
66 a palindrome itself !
and the disposition is depicted in the above picture.