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A318071 Number of nX4 0..1 arrays with every element unequal to 0, 1, 2 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 1
8, 20, 41, 73, 149, 372, 861, 2016, 4901, 11698, 27986, 67359, 161518, 387556, 930666, 2233451, 5360842, 12868595, 30887501, 74139733, 177960357, 427157604, 1025312853, 2461074852, 5907342192, 14179472548, 34035173339, 81695041734 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A318075.

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +a(n-2) +2*a(n-3) -3*a(n-4) -5*a(n-5) -2*a(n-7) +7*a(n-8) -a(n-9) -2*a(n-10) +8*a(n-11) -3*a(n-12) -a(n-13) -3*a(n-14) -3*a(n-15) +4*a(n-16) +a(n-17) -a(n-18) for n>21

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A318075.

Sequence in context: A272995 A273111 A273175 * A308904 A192753 A121307

Adjacent sequences: A318068 A318069 A318070 * A318072 A318073 A318074

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 15 2018

STATUS

approved

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Last modified March 23 23:09 EDT 2023. Contains 361454 sequences. (Running on oeis4.)