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A302218
Number of n X n 0..1 arrays with every element equal to 1, 2 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
0
0, 3, 43, 934, 40395, 3420704, 553097760, 177191137344, 102914156897887, 122108799039662692
OFFSET
1,2
COMMENTS
Diagonal of A302224.
EXAMPLE
Some solutions for n=5
..0..0..0..0..0. .0..0..0..0..0. .0..0..1..1..0. .0..0..0..1..1
..1..1..1..1..1. .1..1..0..0..1. .1..1..1..0..1. .1..0..1..0..1
..1..0..0..0..1. .1..1..1..1..1. .0..0..0..1..0. .0..1..1..0..0
..0..1..1..1..0. .0..0..0..0..0. .1..1..0..1..1. .0..0..0..1..0
..1..0..0..0..0. .0..1..1..1..0. .0..0..1..1..1. .1..1..1..1..1
CROSSREFS
Cf. A302224.
Sequence in context: A141060 A361878 A277496 * A302664 A201784 A364498
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 03 2018
STATUS
approved