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A238722 Number of nX4 0..2 arrays with no element equal to the sum modulo 3 of elements to its left or elements above it 1
4, 16, 86, 284, 1506, 4636, 24298, 73300, 381280, 1144292, 5923512, 17767180, 91688754, 275195668, 1417323260, 4257556764, 21898760846, 65830136636, 338306366754, 1017543445164, 5226264297018, 15725498143268, 80738182410936 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A238726

LINKS

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

FORMULA

Empirical: a(n) = 50*a(n-2) -1020*a(n-4) +11131*a(n-6) -71319*a(n-8) +275531*a(n-10) -629492*a(n-12) +789744*a(n-14) -456320*a(n-16) +76800*a(n-18)

EXAMPLE

Some solutions for n=5

..2..1..2..1....1..2..2..1....2..1..2..1....2..1..1..2....2..1..1..2

..1..2..1..0....2..1..1..2....1..2..1..0....1..0..0..0....1..0..0..0

..2..1..2..0....2..1..2..1....1..2..2..0....1..2..2..0....2..0..0..0

..1..2..1..2....1..0..0..0....2..1..1..0....2..1..1..0....1..0..2..1

..2..1..1..2....2..0..0..0....2..1..1..2....1..0..2..1....2..0..1..1

CROSSREFS

Sequence in context: A298012 A006681 A074876 * A184507 A165964 A300279

Adjacent sequences:  A238719 A238720 A238721 * A238723 A238724 A238725

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 03 2014

STATUS

approved

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Last modified July 12 12:18 EDT 2020. Contains 335661 sequences. (Running on oeis4.)