Number of nX3 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 1 or 3 neighboring 1s.

A296391

Number of nX3 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 1 or 3 neighboring 1s.

Terms

    a(0) =3a(1) =11a(2) =36a(3) =115a(4) =387a(5) =1280a(6) =4237a(7) =14026a(8) =46454a(9) =153800a(10) =509255a(11) =1686210a(12) =5583282a(13) =18486920a(14) =61212645a(15) =202682982a(16) =671109638a(17) =2222130975a(18) =7357763936a(19) =24362510288a(20) =80667430752a(21) =267100323021a(22) =884403804216

External references