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A300376
Number of nX4 0..1 arrays with every element equal to 0, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
1
1, 10, 11, 26, 80, 237, 692, 2548, 8240, 26808, 92281, 309903, 1039489, 3527966, 11931702, 40287280, 136366907, 461541474, 1560895810, 5282067585, 17874953308, 60478794740, 204650044415, 692516520567, 2343315563850, 7929361264807
OFFSET
1,2
COMMENTS
Column 4 of A300380.
FORMULA
Empirical recurrence of order 80 (see link above)
EXAMPLE
Some solutions for n=5
..0..0..1..1. .0..0..0..0. .0..0..0..0. .0..1..0..0. .0..1..1..0
..0..1..0..1. .0..1..0..1. .0..1..0..1. .1..1..0..1. .1..0..1..1
..0..1..1..1. .1..1..0..0. .1..1..1..1. .0..1..0..0. .1..1..0..1
..0..0..0..0. .0..1..0..1. .0..0..0..0. .1..1..0..1. .1..0..0..1
..0..1..0..0. .1..1..1..1. .0..1..0..1. .0..1..1..1. .1..1..1..0
CROSSREFS
Cf. A300380.
Sequence in context: A309357 A051803 A082517 * A136828 A136833 A355631
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 04 2018
STATUS
approved