Number of polybricks: number of ways to arrange n 1 X 2 "bricks" in a wall (see illustrations).

A057973

Number of polybricks: number of ways to arrange n 1 X 2 "bricks" in a wall (see illustrations).

Terms

    a(0) =1a(1) =2a(2) =5a(3) =16a(4) =55a(5) =225a(6) =949a(7) =4269a(8) =19500a(9) =91115a(10) =429742a(11) =2047660a(12) =9820197a(13) =47383255a(14) =229725560a(15) =1118568692a(16) =5466616025a(17) =26804560282a(18) =131817042605a(19) =649952289243

External references