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%I #19 Apr 12 2015 17:34:41
%S 1,1,2,6,15,51,173,681,2682
%N Number of connected digital images in Z^2 (regarding each point as connected to its 8 neighbors) on n points up to isomorphism.
%C Also the number of polyplets (A030222) on n points up to isomorphism of adjacency graphs.
%H P. C. Staecker, <a href="http://arxiv.org/abs/1502.06236">Some enumerations of binary digital images</a>, arXiv 1502.06236 [math.CO], 2015 (see table p. 6).
%H P. C. Staecker, <a href="http://cstaecker.fairfield.edu/~cstaecker/files/research/enumerations/">Digital image enumerations</a>
%e For n=4 the a(4)=6 images are:
%e X X X X XX X X
%e X X X X XX XX XX
%e X X X X X
%e X
%Y Cf. A255539.
%K nonn,hard,more
%O 1,3
%A _P. Christopher Staecker_, Feb 24 2015
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