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A056613 Number of n-celled pseudo-still-lifes in Conway's game of Life. 2
0, 0, 0, 0, 0, 0, 0, 1, 1, 7, 16, 55, 110, 279, 620, 1645, 4067, 10843, 27250, 70637, 179011, 462086, 1184882, 3069135, 7906676, 20463274, 52816265, 136655095, 353198379, 914075620, 2364815358, 6123084116, 15851861075 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,10

COMMENTS

There are two slightly different possible definitions for a pseudo still life: a still life that can be partitioned into exactly two different still lifes, or a still life that can be partitioned into two *or more* still lifes. This sequence uses the latter definition. The first point in the sequence where this makes a difference is a(32) = 6123084116, which would be a(32) = 6123084115 under the former definition. - Nathaniel Johnston, May 25 2017

LINKS

Table of n, a(n) for n=1..33.

S. Ekström, Enumerating Still Lifes (in C)

Mark D. Niemiec, Life Object Counts

EXAMPLE

For n = 8, the unique pseudo-still-life is a pair of 2 X 2 blocks occupying a 5 X 2 bounding box.

CROSSREFS

Cf. A019473.

Sequence in context: A065099 A001345 A225128 * A318413 A183343 A318481

Adjacent sequences:  A056610 A056611 A056612 * A056614 A056615 A056616

KEYWORD

nonn,more,changed

AUTHOR

N. J. A. Sloane, Aug 28 2000

EXTENSIONS

a(24) corrected by Nathaniel Johnston, Aug 26 2016 at the suggestion of Mark Niemiec

a(25)-a(30) computed by Simon Ekström and inserted by Adam P. Goucher, Jan 08 2017

a(24) corrected by Nathaniel Johnston, Feb 21 2017 (computed by Simon Ekström)

a(31)-a(32) from Nathaniel Johnston, using a script made by Simon Ekström, May 25 2017

a(33) from Nathaniel Johnston, using a script made by Simon Ekström, Apr 05 2019

STATUS

approved

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Last modified April 18 22:08 EDT 2019. Contains 322237 sequences. (Running on oeis4.)