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A301945 Number of n X n 0..1 arrays with every element equal to 1, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero. 1
0, 2, 20, 947, 120815, 58609226, 86143630040, 418568449327270, 6527100767589040926, 331808147283786972146018, 54543586667142977292165721500, 29084806316831133817614992597097070 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Diagonal of A301951.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..13

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A301951.

Sequence in context: A006547 A290883 A135757 * A158843 A008793 A015192

Adjacent sequences:  A301942 A301943 A301944 * A301946 A301947 A301948

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 29 2018

STATUS

approved

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Last modified December 8 11:31 EST 2021. Contains 349596 sequences. (Running on oeis4.)