MathDB

We call a sequence of

n

digits one or zero a code. Subsequence of a code is a palindrome if it is the same after we reverse the order of its digits. A palindrome is called nice if its digits occur consecutively in the code. (Code

(1101)

contains

10

palindromes, of which

6

are nice.)
a) What is the least number of palindromes in a code?
b) What is the least number of nice palindromes in a code?

Problem Statement