Number of tilings of a 2 X n rectangle using integer-sided rectangular tiles of equal area.

Terms

a(0) =1a(1) =2a(2) =4a(3) =6a(4) =9a(5) =11a(6) =21a(7) =24a(8) =43a(9) =62a(10) =102a(11) =147a(12) =259a(13) =380a(14) =636a(15) =1003a(16) =1640a(17) =2587a(18) =4258a(19) =6768a(20) =11053a(21) =17740a(22) =28806a(23) =46371a(24) =75318a(25) =121405a(26) =196800a(27) =317874a(28) =514870a(29) =832043