A197959 - OEIS

%I #8 Dec 05 2014 02:28:18

%S 1,3,7,28,99,433,1852,8463,38797,181888,858560,4093728,19636098,

%T 94758985

%N Number of free poly-IH13-tiles (holes allowed) with n cells.

%D Branko Grünbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987, Sections 6.2 and 9.4.

%Y Cf. A197958.

%K hard,nonn

%O 1,2

%A _Joseph Myers_, Oct 19 2011