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A127560 Number of fixed r-celled polyominoes with smallest containing rectangle measuring k by m, read in order r=A056556(n)+1, k=A056560(n)+1, m=A056558(n)+1. 0
1, 0, 1, 1, 0, 0, 0, 1, 4, 1, 0, 0, 0, 0, 1, 0, 1, 8, 8, 1, 0, 0, 0, 0, 0, 0, 0, 6, 6, 0, 1, 12, 25, 12, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 18, 44, 18, 0, 1, 16, 50, 50, 16, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 32, 8, 0, 0, 38, 155, 155, 38, 0, 1, 20, 82, 120, 82, 20, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,9

COMMENTS

The sum of each triangle, i.e. for a given r the sum of a(n) for all n such that r=A056556(n)+1 is the number of r-celled fixed polyominoes, A001168(r).

LINKS

Table of n, a(n) for n=0..83.

EXAMPLE

The 5th triangle of the sequence, the number of fixed pentominoes by dimension, is

0,0,0,0,1

0,0,6,12

0,6,25

0,12

1

This indicates, for example, there are 25 fixed pentominos that fit in a 3 X 3 rectangle and 12 fixed pentominos that fit in a 4 X 2 rectangle.

CROSSREFS

Cf. A000105, A000988, A001168 Indices for reading by triangles given by A056556, A056560, A056558.

Sequence in context: A320742 A093318 A255329 * A098172 A049759 A265421

Adjacent sequences:  A127557 A127558 A127559 * A127561 A127562 A127563

KEYWORD

nonn

AUTHOR

Graeme McRae, Jan 18 2007

STATUS

approved

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Last modified September 20 11:42 EDT 2021. Contains 347584 sequences. (Running on oeis4.)