Colouring a Strip (noch nicht übersetzt)

Problem 670

A certain type of tile comes in three different sizes - 1×1, 1×2, and 1×3 - and in four different colours: blue, green, red and yellow. There is an unlimited number of tiles available in each combination of size and colour.

These are used to tile a 2×n rectangle, where n is a positive integer, subject to the following conditions:

  • The rectangle must be fully covered by non-overlapping tiles.
  • It is not permitted for four tiles to have their corners meeting at a single point.
  • Adjacent tiles must be of different colours.

For example, the following is an acceptable tiling of a 2×12 rectangle:

Acceptable colouring

but the following is not an acceptable tiling, because it violates the "no four corners meeting at a point" rule:

Unacceptable colouring

Let F(n) be the number of ways the 2×n rectangle can be tiled subject to these rules. Where reflecting horizontally or vertically would give a different tiling, these tilings are to be counted separately.

For example, F(2)=120, F(5)=45876, and F(100)53275818(mod1000004321).

Find F(1016)mod1000004321.