Number of (n+1) X (1+1) 0..1 arrays with each 2 X 2 subblock having clockwise pattern 0000 0011 or 0111.

A259243

Number of (n+1) X (1+1) 0..1 arrays with each 2 X 2 subblock having clockwise pattern 0000 0011 or 0111.

Terms

    a(0) =9a(1) =21a(2) =48a(3) =111a(4) =255a(5) =588a(6) =1353a(7) =3117a(8) =7176a(9) =16527a(10) =38055a(11) =87636a(12) =201801a(13) =464709a(14) =1070112a(15) =2464239a(16) =5674575a(17) =13067292a(18) =30091017a(19) =69292893a(20) =159565944a(21) =367444623a(22) =846142455a(23) =1948476324a(24) =4486903689a(25) =10332332661a(26) =23793043728a(27) =54790041711

External references