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A255540 Number of connected digital images in Z^2 (regarding each point as connected to its 8 neighbors) on n points up to isomorphism. 0
1, 1, 2, 6, 15, 51, 173, 681, 2682 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Also the number of polyplets (A030222) on n points up to isomorphism of adjacency graphs.

LINKS

Table of n, a(n) for n=1..9.

P. C. Staecker, Some enumerations of binary digital images, arXiv 1502.06236 [math.CO], 2015 (see table p. 6).

P. C. Staecker, Digital image enumerations

EXAMPLE

For n=4 the a(4)=6 images are:

X   X X    X    XX    X     X

X    X    X X   XX   XX   XX

X    X     X         X     X

X

CROSSREFS

Cf. A255539.

Sequence in context: A237262 A291848 A196961 * A323926 A256982 A047870

Adjacent sequences:  A255537 A255538 A255539 * A255541 A255542 A255543

KEYWORD

nonn,hard,more

AUTHOR

P. Christopher Staecker, Feb 24 2015

STATUS

approved

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Last modified August 10 16:24 EDT 2022. Contains 356039 sequences. (Running on oeis4.)