MathDB
palindromes using 5 diff. letters under conditions

Source: Dutch NMO 2006 p1

September 21, 2019
number theorypalindromes

Problem Statement

A palindrome is a word that doesn't matter if you read it from left to right or from right to left. Examples: OMO, lepel and parterretrap. How many palindromes can you make with the five letters a,b,c,da, b, c, d and ee under the conditions: - each letter may appear no more than twice in each palindrome, - the length of each palindrome is at least 33 letters. (Any possible combination of letters is considered a word.)