0,2
From Vicher's table.
Table of n, a(n) for n=0..4.
M. Keller, Counting Polyforms
M. Vicher, Polyforms
Sequence in context: A037540 A037484 A013566 * A273232 A064546 A217872
Adjacent sequences: A056766 A056767 A056768 * A056770 A056771 A056772
nonn
James A. Sellers, Aug 28 2000
Edited by T. D. Noe, Apr 09 2009
approved
