A255537 Number of connected pointed-irreducible digital images of n points up to homotopy equivalence.

1, 0, 0, 0, 1, 2, 9, 68, 1110

Offset

1,6

Comments

"Pointed-irreducible" means that the identity map is not homotopic to any nonsurjective map having a fixed point.

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.

Crossrefs

Cf. A248571.

Sequence in context: A020563 A354730 A193160 * A272663 A006849 A319285

Adjacent sequences: A255534 A255535 A255536 * A255538 A255539 A255540

Keyword

nonn,more,hard

Author

P. Christopher Staecker, Feb 24 2015

Status

approved