T(n,k)=Number of nXk 0..4 arrays with some element plus some horizontally or vertically adjacent neighbor totalling four exactly once.

A270058

T(n,k)=Number of nXk 0..4 arrays with some element plus some horizontally or vertically adjacent neighbor totalling four exactly once.

Terms

    a(0) =0a(1) =5a(2) =5a(3) =40a(4) =240a(5) =40a(6) =240a(7) =5400a(8) =5400a(9) =240a(10) =1280a(11) =99840a(12) =385200a(13) =99840a(14) =1280a(15) =6400a(16) =1683240a(17) =22911300a(18) =22911300a(19) =1683240a(20) =6400a(21) =30720a(22) =26891280a(23) =1248460920a(24) =4410058320a(25) =1248460920a(26) =26891280a(27) =30720a(28) =143360a(29) =414705720

External references