Half the number of (n+1) X 3 0..2 arrays with every 2 X 2 subblock having two or four distinct clockwise edge differences.
A209505
Half the number of (n+1) X 3 0..2 arrays with every 2 X 2 subblock having two or four distinct clockwise edge differences.
Terms
- a(0) =27a(1) =123a(2) =561a(3) =2559a(4) =11673a(5) =53247a(6) =242889a(7) =1107951a(8) =5053977a(9) =23053983a(10) =105161961a(11) =479701839a(12) =2188185273a(13) =9981522687a(14) =45531242889a(15) =207693169071a(16) =947403359577
External references
- oeis: A209505