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A281406 Number of 7Xn 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, 2692, 10226, 17194, 30959, 51940, 84474, 129934, 192666, 283820, 424420, 643532, 984928, 1523312, 2366752, 3680140, 5732310, 8944680, 13964678, 21804068, 34052814, 53174028, 82984728, 129437616, 201787582, 314380720, 489483020 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Row 7 of A281400.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) -6*a(n-2) +6*a(n-3) -7*a(n-4) +6*a(n-5) -3*a(n-6) +4*a(n-7) -7*a(n-8) +6*a(n-9) -4*a(n-10) +4*a(n-11) -2*a(n-12) -a(n-14) +2*a(n-15) -a(n-16) for n>31
EXAMPLE
Some solutions for n=4
..0..0..1..0. .0..0..1..1. .0..0..1..0. .0..0..1..0. .0..1..1..0
..0..1..1..0. .1..0..1..0. .1..1..0..1. .0..1..1..0. .0..0..1..1
..0..1..0..0. .0..0..1..1. .0..1..0..1. .1..0..1..0. .1..0..1..0
..0..1..0..1. .1..1..0..0. .0..0..0..1. .1..0..1..0. .0..0..1..0
..1..1..0..0. .0..1..0..1. .0..1..0..1. .0..1..0..1. .1..1..0..1
..0..0..1..0. .1..1..0..1. .0..1..0..0. .0..1..0..1. .0..1..0..1
..1..0..1..1. .0..0..1..1. .1..1..1..0. .1..1..0..0. .1..1..0..1
CROSSREFS
Cf. A281400.
Sequence in context: A185748 A252404 A020424 * A111027 A245529 A210049
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 21 2017
STATUS
approved

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Last modified July 12 13:24 EDT 2024. Contains 374247 sequences. (Running on oeis4.)