Number of (n+2)X(4+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00010101 00100101 or 01010101.

A261261

Number of (n+2)X(4+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00010101 00100101 or 01010101.

Terms

    a(0) =166a(1) =232a(2) =690a(3) =1918a(4) =4350a(5) =10382a(6) =26072a(7) =63964a(8) =155288a(9) =379950a(10) =931560a(11) =2278454a(12) =5570500a(13) =13629422a(14) =33349058a(15) =81580648a(16) =199570734a(17) =488243484a(18) =1194455224a(19) =2922102016a(20) =7148645416a(21) =17488560724a(22) =42784191822a(23) =104667572730a(24) =256059752954

External references