Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000101 or 00001011.

A261548

Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000101 or 00001011.

Terms

    a(0) =48a(1) =80a(2) =170a(3) =336a(4) =652a(5) =1293a(6) =2588a(7) =5100a(8) =9996a(9) =19788a(10) =39102a(11) =76977a(12) =151492a(13) =298988a(14) =589456a(15) =1160987a(16) =2287512a(17) =4509948a(18) =8887914a(19) =17512005a(20) =34511260a(21) =68019255a(22) =134042352a(23) =264143499a(24) =520558296a(25) =1025893511a(26) =2021700618a(27) =3984123909

External references