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A156228 Number of lakes in Conway's Game of Life with 8*n cells. 0
1, 0, 1, 1, 4, 7, 31, 98, 446, 1894, 9049, 43151 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

a(n) is also the number of walks of length 4*n on a 2D lattice with the properties that: it turns 90 degrees after every step of length 1, it is a closed loop (ie. it ends where it started) and it never crosses itself.

LINKS

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

N. Johnston, Counting Lakes

LifeWiki, Lakes

EXAMPLE

a(2) = 0 because there are no lakes with 16 cells.

CROSSREFS

Cf. A019473

Sequence in context: A080871 A102666 A123801 * A218959 A283332 A000289

Adjacent sequences:  A156225 A156226 A156227 * A156229 A156230 A156231

KEYWORD

hard,more,nonn

AUTHOR

Nathaniel Johnston, Feb 06 2009

EXTENSIONS

a(11) and a(12) added by Nathaniel Johnston, Mar 09 2009

STATUS

approved

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Last modified October 20 17:48 EDT 2018. Contains 316396 sequences. (Running on oeis4.)