Number of tilings of a 5 X n rectangle using right trominoes and 2 X 2 tiles.

Terms

a(0) =1a(1) =0a(2) =4a(3) =0a(4) =16a(5) =0a(6) =136a(7) =0a(8) =1128a(9) =384a(10) =8120a(11) =6912a(12) =60904a(13) =75136a(14) =491960a(15) =720640a(16) =4023592a(17) =6828928a(18) =32819320a(19) =63472640a(20) =270471784a(21) =574543744a(22) =2256221368a(23) =5119155712a(24) =18940876712a(25) =45266369152a(26) =159625747960a(27) =397949457408