Number of nX3 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

A268804

Number of nX3 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

Terms

    a(0) =24a(1) =104a(2) =332a(3) =1202a(4) =4158a(5) =14308a(6) =48460a(7) =162722a(8) =541744a(9) =1791504a(10) =5889586a(11) =19264864a(12) =62738690a(13) =203528858a(14) =658003018a(15) =2120809106a(16) =6816832928a(17) =21856821554a(18) =69922091542a(19) =223229394256a(20) =711333766468

External references