Search Problems   RSS Feed
projecteuler.net

Tours on a $4 \times N$ Playing Board

 Published on Saturday, 21st March 2009, 01:00 pm and solved by 2139
Difficulty: Level 16 [43%]

Problem 237

Let $T(n)$ be the number of tours over a $4 \times n$ playing board such that:

  • The tour starts in the top left corner.
  • The tour consists of moves that are up, down, left, or right one square.
  • The tour visits each square exactly once.
  • The tour ends in the bottom left corner.

The diagram shows one tour over a $4 \times 10$ board:

$T(10)$ is $2329$. What is $T(10^{12})$ modulo $10^8$?



Copied to Clipboard