login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A293261
Number of fixed polyominoes without holes that have a width and height of n.
2
1, 5, 106, 6074, 943340, 419355340, 554485727288, 2208574156731474, 26609978139626497670, 973224195603423767343946, 108342096917091380628767818812, 36763211016528549310068224122368860, 38044287043749436284594644308861499605492
OFFSET
1,2
COMMENTS
Equivalently, the number of cycles on an (n+1) X (n+1) grid that touch each of the four outside edges.
LINKS
Andrey Zabolotskiy, Table of n, a(n) for n = 1..16
Anthony J. Guttmann and Iwan Jensen, Effect of Confinement: Polygons in Strips, Slabs and Rectangles, in: Polygons, Polyominoes and Polycubes, LNP 775, Springer, 2009. See Table 10.2 on p. 239.
CROSSREFS
Main diagonal of A232103.
Cf. A268404.
Sequence in context: A059490 A204109 A093979 * A324230 A142479 A204110
KEYWORD
nonn
AUTHOR
Andrew Howroyd, Oct 04 2017
STATUS
approved