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A301818 Number of nXn 0..1 arrays with every element equal to 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero. 1
0, 2, 4, 68, 1197, 31061, 2341241, 221373169, 47059520355, 17662862033686, 11449618914826511, 15088557751754929900, 33289512591289837483184, 143748055903459113756507351, 1108648718940092116466729395935 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Diagonal of A301823.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..16

EXAMPLE

Some solutions for n=5

..0..0..1..1..0. .0..0..0..1..1. .0..0..1..1..1. .0..0..0..1..1

..0..1..1..0..0. .1..1..0..0..1. .0..1..0..0..1. .1..1..0..0..0

..0..0..1..1..1. .1..1..0..1..1. .1..1..0..1..0. .1..1..1..1..1

..0..1..0..1..1. .1..0..0..0..0. .1..0..1..0..1. .0..0..0..0..0

..1..0..0..1..1. .1..1..1..0..0. .1..1..0..1..1. .1..1..1..1..1

CROSSREFS

Cf. A301823.

Sequence in context: A279969 A018364 A100603 * A054920 A062061 A066974

Adjacent sequences:  A301815 A301816 A301817 * A301819 A301820 A301821

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 27 2018

STATUS

approved

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Last modified August 19 08:14 EDT 2019. Contains 326115 sequences. (Running on oeis4.)