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A281399 Number of nX7 0..1 arrays with no element equal to more than two of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards. 1
0, 1296, 2364, 6276, 16241, 37462, 84474, 185834, 400854, 871302, 1899789, 4111556, 8868230, 19130914, 41172419, 88375862, 189462087, 405538634, 866448924, 1848700340, 3939571575, 8383924848, 17820831178, 37839585622, 80261619670 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Column 7 of A281400.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) -a(n-2) +5*a(n-3) -15*a(n-4) -7*a(n-5) +26*a(n-7) +34*a(n-8) -8*a(n-9) -16*a(n-10) -40*a(n-11) -16*a(n-12) -26*a(n-13) +5*a(n-14) +59*a(n-15) +33*a(n-16) +3*a(n-17) -18*a(n-18) -2*a(n-19) -15*a(n-20) -21*a(n-21) +9*a(n-22) +9*a(n-23) for n>38
EXAMPLE
Some solutions for n=4
..0..1..0..0..1..0..1. .0..0..1..0..1..0..1. .0..1..0..0..1..1..0
..0..1..1..0..1..0..1. .1..0..1..0..0..0..1. .0..1..1..0..1..0..0
..0..1..0..0..1..0..0. .0..0..1..0..1..0..1. .0..0..1..0..1..0..1
..1..1..0..1..1..1..0. .0..1..1..0..1..0..1. .1..0..1..1..1..0..1
CROSSREFS
Cf. A281400.
Sequence in context: A273631 A186486 A186485 * A043372 A372841 A217908
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 21 2017
STATUS
approved

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Last modified May 26 04:31 EDT 2024. Contains 372807 sequences. (Running on oeis4.)