[ July 27, 2003 ]
Expressions with a palindromic look.

Here is an expression that I wrote down a while ago.
When you consider only its digits you'll notice
that we deal here with a palindrome ie, 3233223323.

(3^2)^3 + ((3^2)2)^3 = 3^(2^3)

equivalent to 729 + 5832 = 6561 or 9³ + 18³ = 3⁸.

A neat fact published in newsgroup sci.math.
and announced as a " multi-palindromic bi-digital curiosity ".
by Don Mcdonald dd. Sep 29 1996.

Exist there other non-trivial expressions possessing such a
beautiful palindromic (symmetrical) look regarding its digits ?

The 37^th Mersenne Prime
2^3021377 — 1
has a prime exponent that can be rewritten
as a palindromic expression in the following manner

3021377 = 1 * 2 * 34 * 44432 + 1

and 1234444321 is a beautiful palindromic number.
A neat fact published in newsgroup rec.puzzles
makes this " an easy to remember mersenne prime ".
also by Don Mcdonald dd. May 15 2000.