Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010101 00101011 or 01010101.

A260921

Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010101 00101011 or 01010101.

Terms

    a(0) =48a(1) =68a(2) =146a(3) =279a(4) =468a(5) =831a(6) =1528a(7) =2750a(8) =4874a(9) =8781a(10) =15768a(11) =28326a(12) =50656a(13) =91181a(14) =163232a(15) =293511a(16) =525366a(17) =945120a(18) =1691614a(19) =3042584a(20) =5446082a(21) =9796167a(22) =17533998a(23) =31538640a(24) =56451580a(25) =101540858a(26) =181748282a(27) =326914782a(28) =585147672a(29) =1052518323

External references