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A301960 Number of nX4 0..1 arrays with every element equal to 0, 1 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero. 1
5, 9, 25, 64, 169, 441, 1156, 3025, 7921, 20736, 54289, 142129, 372100, 974169, 2550409, 6677056, 17480761, 45765225, 119814916, 313679521, 821223649, 2149991424, 5628750625, 14736260449, 38580030724, 101003831721, 264431464441 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A301964.

LINKS

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

FORMULA

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

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A301964.

Sequence in context: A137199 A221567 A147512 * A050359 A062812 A032499

Adjacent sequences:  A301957 A301958 A301959 * A301961 A301962 A301963

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 29 2018

STATUS

approved

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Last modified August 12 19:59 EDT 2022. Contains 356077 sequences. (Running on oeis4.)