Number of (n+1) X (1+1) 0..3 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings).

A235282

Number of (n+1) X (1+1) 0..3 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings).

Terms

    a(0) =20a(1) =40a(2) =68a(3) =136a(4) =236a(5) =472a(6) =836a(7) =1672a(8) =3020a(9) =6040a(10) =11108a(11) =22216a(12) =41516a(13) =83032a(14) =157316a(15) =314632a(16) =603020a(17) =1206040a(18) =2333348a(19) =4666696a(20) =9097196a(21) =18194392a(22) =35680196a(23) =71360392a(24) =140595020a(25) =281190040a(26) =556002788a(27) =1112005576a(28) =2204879276a(29) =4409758552

External references