

A056845


Number of polydiamonds: polyominoes made from n diamonds (another version).


1




OFFSET

1,2


COMMENTS

The difference between this and A056844 is not clear to me. Maybe the definition of equivalence has been changed, or the rules concerning planarity or the existence of holes have changed.
Comment from Larry_Reeves(AT)intranetsolutions.com, Jun 22 2001: If you look at Vicher's picture of the 40 4celled polydiamonds (link in A056844), near the middle of the picture is a polydiamond that looks like the traditional 2D representation of a cube with an extra diamond stuck to the edge. Depending on how you orient the cube, there are actually 2 different ways to form this polydiamond, although there is no change in the perimeter shape. I haven't confirmed that this explains the difference in values for sizes 5 and above, but it looks like a possible explanation.


LINKS

Table of n, a(n) for n=1..6.
M. Keller, More information
M. Vicher, Polyforms


CROSSREFS

Cf. A056844.
Sequence in context: A152052 A192661 A020038 * A162273 A289684 A280955
Adjacent sequences: A056842 A056843 A056844 * A056846 A056847 A056848


KEYWORD

obsc,nonn,more


AUTHOR

James A. Sellers, Aug 28 2000


STATUS

approved



