Number of (n+2)X(3+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00000011 or 00001111.

A260365

Number of (n+2)X(3+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00000011 or 00001111.

Terms

    a(0) =208a(1) =342a(2) =912a(3) =2014a(4) =2532a(5) =5806a(6) =13632a(7) =20576a(8) =39376a(9) =91830a(10) =156768a(11) =279744a(12) =621988a(13) =1154372a(14) =2028560a(15) =4261442a(16) =8304084a(17) =14800068a(18) =29615732a(19) =58935832a(20) =107612892a(21) =208478370a(22) =415856628a(23) =777318530a(24) =1480611488a(25) =2931957688a(26) =5578603544

External references