Number of (n+2) X (3+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010101 01010101 or 01010111.

A260133

Number of (n+2) X (3+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010101 01010101 or 01010111.

Terms

    a(0) =138a(1) =342a(2) =1162a(3) =2966a(4) =7698a(5) =22522a(6) =61914a(7) =165954a(8) =462030a(9) =1279574a(10) =3493270a(11) =9617162a(12) =26547878a(13) =72931662a(14) =200533394a(15) =552344746a(16) =1519650534a(17) =4179817642a(18) =11503670758a(19) =31655891034a(20) =87092868954a(21) =239649098010a(22) =659447987986

External references