Number of profiles in domino tiling of a 2*n checkboard.

Terms

a(0) =0a(1) =1a(2) =2a(3) =9a(4) =12a(5) =50a(6) =60a(7) =245a(8) =280a(9) =1134a(10) =1260a(11) =5082a(12) =5544a(13) =22308a(14) =24024a(15) =96525a(16) =102960a(17) =413270a(18) =437580a(19) =1755182a(20) =1847560a(21) =7407036a(22) =7759752a(23) =31097794a(24) =32449872a(25) =130007500a(26) =135207800a(27) =541574100a(28) =561632400a(29) =2249204040