Number of n X 3 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 1 1 1 vertically.

Terms

a(0) =6a(1) =36a(2) =72a(3) =166a(4) =360a(5) =660a(6) =1292a(7) =2400a(8) =4396a(9) =8096a(10) =14580a(11) =26346a(12) =47336a(13) =84502a(14) =150976a(15) =268594a(16) =477130a(17) =846850a(18) =1500112a(19) =2655880a(20) =4697786a(21) =8303004a(22) =14669200a(23) =25901790a(24) =45719422a(25) =80675866a(26) =142317030a(27) =251007562a(28) =442623618a(29) =780396916