Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000000 00000001 or 00000011.

A259888

Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000000 00000001 or 00000011.

Terms

    a(0) =67a(1) =174a(2) =653a(3) =1853a(4) =4662a(5) =13704a(6) =40955a(7) =114098a(8) =320200a(9) =925820a(10) =2650721a(11) =7507059a(12) =21402747a(13) =61226147a(14) =174506650a(15) =497034443a(16) =1418169080a(17) =4046094873a(18) =11534896627a(19) =32891041296a(20) =93814175452a(21) =267543153907a(22) =762917347904

External references