Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000011 or 00001001.

A260287

Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000011 or 00001001.

Terms

    a(0) =48a(1) =104a(2) =274a(3) =560a(4) =966a(5) =2300a(6) =4762a(7) =8252a(8) =17470a(9) =38160a(10) =71698a(11) =142360a(12) =304646a(13) =599716a(14) =1172578a(15) =2447716a(16) =4949782a(17) =9718248a(18) =19837162a(19) =40474736a(20) =80338222a(21) =161965772a(22) =330213194a(23) =661573644a(24) =1327566094a(25) =2695382016a(26) =5430701122

External references