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A279581 Number of 2 X n 0..2 arrays with no element equal to a strict majority of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards. 1
0, 4, 36, 304, 2212, 15428, 103648, 680052, 4380964, 27829504, 174806900, 1087994628, 6720111376, 41240210276, 251687871332, 1528700226512, 9246173840644, 55718099241732, 334660112687936, 2004174865390100 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
Empirical: a(n) = 12*a(n-1) - 36*a(n-2) - 22*a(n-3) + 140*a(n-4) - 48*a(n-5) - 121*a(n-6) + 88*a(n-7) - 16*a(n-8).
Empirical g.f.: 4*x^2*(1 - x)*(1 - 3*x + x^2)*(1 + x + 4*x^2) / (1 - 6*x + 11*x^3 - 4*x^4)^2. - Colin Barker, Feb 11 2019
EXAMPLE
Some solutions for n=4:
..0..1..2..1. .0..0..1..2. .0..1..1..2. .0..0..1..0. .0..1..0..2
..0..1..1..2. .1..0..0..1. .2..1..0..1. .1..0..1..2. .1..1..0..2
CROSSREFS
Row 2 of A279580.
Sequence in context: A241104 A361554 A222428 * A093186 A000765 A226283
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 15 2016
STATUS
approved

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Last modified June 22 06:19 EDT 2024. Contains 373565 sequences. (Running on oeis4.)