Number of n X 3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 neighboring 1.

A297390

Number of n X 3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 neighboring 1.

Terms

    a(0) =3a(1) =9a(2) =19a(3) =57a(4) =139a(5) =369a(6) =963a(7) =2489a(8) =6523a(9) =16929a(10) =44147a(11) =114953a(12) =299307a(13) =779697a(14) =2030243a(15) =5287833a(16) =13770971a(17) =35864001a(18) =93402579a(19) =243249193a(20) =633503627a(21) =1649849553a(22) =4296752131a(23) =11190160825a(24) =29142853947a(25) =75897603297a(26) =197662332211

External references