Number of (n+2) X (4+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010001 00010101 or 01010101.

A261109

Number of (n+2) X (4+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010001 00010101 or 01010101.

Terms

    a(0) =97a(1) =206a(2) =566a(3) =1498a(4) =3908a(5) =10268a(6) =27030a(7) =70980a(8) =186290a(9) =489516a(10) =1286458a(11) =3379154a(12) =8876106a(13) =23319066a(14) =61261972a(15) =160934256a(16) =422777430a(17) =1110660098a(18) =2917747758a(19) =7665011686a(20) =20136272074a(21) =52898777022a(22) =138967021622a(23) =365071414304

External references