Number of 2Xn 0..1 arrays with row sums equal and column sums unequal to adjacent columns.

Terms

a(0) =2a(1) =2a(2) =6a(3) =22a(4) =54a(5) =102a(6) =214a(7) =582a(8) =1590a(9) =3814a(10) =8662a(11) =20934a(12) =53942a(13) =137190a(14) =335574a(15) =815942a(16) =2032694a(17) =5139942a(18) =12902614a(19) =32059846a(20) =79807158a(21) =200325350a(22) =504502230a(23) =1267146054a(24) =3176193590a(25) =7975495910a(26) =20082938838a(27) =50611676614a(28) =127466481334