A340341 Number of polymings with n cells, distinguishing mirror images.

1, 3, 16, 129, 1009, 8997, 80816, 746483, 6983847, 66146105, 632186200, 6089173570

Offset

1,2

Comments

A polyming is a generalized polyiamond whose cells may be joined at corners as well as at edges. I introduced the term in 2010. In A319324 and elsewhere, David Bevan calls these shapes "polyglasses." In A239658, Abe Wits and Ragnar Groot Koerkamp call them simply "triangular polyplets."

Links

Table of n, a(n) for n=1..12.

G. L. Sicherman, Catalogue of Polymings

Example

a(3)=16, because there are 11 two-sided 3-mings (identifying mirror images), and 5 of them are chiral.  See the link above.

Crossrefs

Cf. A239658, A319324.

Sequence in context: A264636 A208829 A289145 * A362661 A368791 A135752

Adjacent sequences: A340338 A340339 A340340 * A340342 A340343 A340344

Keyword

nonn,hard,more

Author

George Sicherman, Jan 04 2021

Extensions

a(11) and a(12) from Aaron N. Siegel, May 22 2022

Status

approved