387352domain: NAppears in sequencesNumber of tilings of an n X 1 rectangle by tiles of dimension 1 X 1 and 2 X 1 such that every tile is next to a tile of different size.at n=43A245596Expansion of Product_{n>=1} ((1 + (2*x)^n)/(1 - (2*x)^n))^(1/2).at n=13A303307