%I #6 Mar 30 2012 16:48:52
%S 1,12,94,604,3463,18440,93274,454412,2151673,9964500,45335002,
%T 203303760,900901387,3952468348,17194102478,74257185512,318693463933,
%U 1360298775524,5778468266446,24442845038580
%N Number of staircase polygons of perimeter 2n with one (staircase polygon) hole on square lattice (not allowing rotations).
%H I. Jensen, <a href="/A057410/b057410.txt">Table of n, a(n) for n = 8..103</a> (from link below)
%H I. Jensen, <a href="http://www.ms.unimelb.edu.au/~iwan/polygons/series/staircase.perim.1hole.ser">More terms</a>
%K nonn
%O 8,2
%A _N. J. A. Sloane_, Aug 30 2000, corrected Aug 29 2006