Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000101 00010101 or 01010101.

A260009

Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000101 00010101 or 01010101.

Terms

    a(0) =49a(1) =98a(2) =252a(3) =578a(4) =1232a(5) =2738a(6) =6262a(7) =14112a(8) =31500a(9) =70688a(10) =159198a(11) =357858a(12) =803428a(13) =1805000a(14) =4056988a(15) =9116450a(16) =20482308a(17) =46022418a(18) =103415312a(19) =232373682a(20) =522131898a(21) =1173216800a(22) =2636206832a(23) =5923508168a(24) =13309979250a(25) =29907242450a(26) =67201004772

External references