Number of (n+2) X (5+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000101 00010001 or 00010101.

A260606

Number of (n+2) X (5+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000101 00010001 or 00010101.

Terms

    a(0) =525a(1) =1136a(2) =3343a(3) =8736a(4) =26148a(5) =70906a(6) =217376a(7) =587980a(8) =1803868a(9) =4887108a(10) =15001422a(11) =40649252a(12) =124739782a(13) =337833308a(14) =1037043054a(15) =2809741952a(16) =8622275444a(17) =23356067132a(18) =71689360248a(19) =194209294956a(20) =596026346284

External references