T(n,k)=Number of nXk 0..3 arrays with some element plus some horizontally or vertically adjacent neighbor totalling three no more than once.

A269109

T(n,k)=Number of nXk 0..3 arrays with some element plus some horizontally or vertically adjacent neighbor totalling three no more than once.

Terms

    a(0) =4a(1) =16a(2) =16a(3) =60a(4) =180a(5) =60a(6) =216a(7) =1740a(8) =1740a(9) =216a(10) =756a(11) =15540a(12) =40908a(13) =15540a(14) =756a(15) =2592a(16) =132300a(17) =872460a(18) =872460a(19) =132300a(20) =2592a(21) =8748a(22) =1090740a(23) =17593092a(24) =43964700a(25) =17593092a(26) =1090740a(27) =8748a(28) =29160a(29) =8787660

External references