

A098891


Define the nomino graph to be the graph whose vertices are each of the nominoes, two of which are joined by an edge if one can be obtained from the other by cutting out one of the latter's component squares (thus obtaining an (n1)omino for most cases) and gluing it elsewhere. The sequence counts the edges in these graphs.


1



0, 0, 1, 8, 47, 266, 1339, 6544, 29837, 133495, 585002, 2542563
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,4


COMMENTS

In some cases the act of removing a component square (temporarily) disconnects the polyomino before the component is reattached elsewhere.  Sean A. Irvine, Apr 13 2020


LINKS

Table of n, a(n) for n=1..12.
Freddy Barrera, Picture for a(5), 2020.
Freddy Barrera, Picture for a(6), 2020.
Sean A. Irvine, Java program (github)
FUNG Cheok Yin, Tetrominoes
FUNG Cheok Yin, Maxima code for n = 4 and n = 5, Apr 13 2020


CROSSREFS

Sequence in context: A296631 A255720 A014524 * A054488 A034349 A296797
Adjacent sequences: A098888 A098889 A098890 * A098892 A098893 A098894


KEYWORD

nonn,more


AUTHOR

Bernardo Recamán (ignotus(AT)hotmail.com), Nov 08 2004


EXTENSIONS

a(4) corrected by FUNG Cheok Yin, Feb 11 2020
a(5) corrected and a(6)a(12) from Sean A. Irvine and Freddy Barrera, Apr 13 2020


STATUS

approved



