Number of nX2 0..1 arrays with every element unequal to 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
A317817
Number of nX2 0..1 arrays with every element unequal to 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
Terms
- a(0) =1a(1) =5a(2) =16a(3) =50a(4) =160a(5) =511a(6) =1634a(7) =5226a(8) =16716a(9) =53471a(10) =171045a(11) =547149a(12) =1750258a(13) =5598852a(14) =17910021a(15) =57291907a(16) =183269625a(17) =586256561a(18) =1875361283a(19) =5999045795a(20) =19190195958a(21) =61387032829a(22) =196369427849a(23) =628161199864
External references
- oeis: A317817