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A302146 Number of nX3 0..1 arrays with every element equal to 0, 2, 3 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero. 1
1, 2, 4, 10, 28, 84, 260, 816, 2576, 8152, 25824, 81840, 259408, 822304, 2606720, 8263456, 26195776, 83042752, 263252544, 834533120, 2645541888, 8386596224, 26586234880, 84280663296, 267176990976, 846974167552, 2684981361664 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 3 of A302150.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 4*a(n-1) -2*a(n-2) -2*a(n-3)

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A302150.

Sequence in context: A192653 A149824 A331938 * A202135 A068875 A262543

Adjacent sequences:  A302143 A302144 A302145 * A302147 A302148 A302149

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 02 2018

STATUS

approved

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Last modified December 4 04:22 EST 2020. Contains 338921 sequences. (Running on oeis4.)