Number of staircase polygons of area n with one (staircase polygon) hole on square lattice (not allowing rotations).
1, 4, 18, 62, 205, 624, 1841, 5214, 14448, 39118, 104281, 273900, 711416, 1828950
1 seqfan posts
Sat Feb 14 17:48:59 CET 2009 [seqfan] Re: Staircase Polygons (with a Rotated Staircase hole) by perimeter