Boustrophedon transform of squares.

Terms

a(0) =1a(1) =5a(2) =18a(3) =57a(4) =180a(5) =617a(6) =2400a(7) =10717a(8) =54544a(9) =312353a(10) =1988104a(11) =13921501a(12) =106350816a(13) =880162337a(14) =7844596536a(15) =74910367309a(16) =763030711936