Number of (n+1) X (3+1) 0..1 arrays with each 2 X 2 subblock having clockwise pattern 0000 0011 or 0101.

A259217

Number of (n+1) X (3+1) 0..1 arrays with each 2 X 2 subblock having clockwise pattern 0000 0011 or 0101.

Terms

    a(0) =24a(1) =40a(2) =66a(3) =112a(4) =192a(5) =334a(6) =588a(7) =1048a(8) =1890a(9) =3448a(10) =6360a(11) =11854a(12) =22308a(13) =42352a(14) =81042a(15) =156160a(16) =302736a(17) =589966a(18) =1154844a(19) =2269096a(20) =4472514a(21) =8838760a(22) =17505576a(23) =34732942a(24) =69015732a(25) =137303104a(26) =273427698a(27) =544948528a(28) =1086811680a(29) =2168631118

External references