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A281061
Number of 6Xn 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.
1
0, 468, 4988, 10112, 22106, 46610, 87995, 159317, 282552, 495655, 864369, 1501627, 2601791, 4498333, 7762266, 13369326, 22983871, 39440039, 67556367, 115513187, 197179026, 336035590, 571793109, 971529387, 1648428839, 2793279473
OFFSET
1,2
COMMENTS
Row 6 of A281056.
LINKS
FORMULA
Empirical: a(n) = 6*a(n-1) -12*a(n-2) +5*a(n-3) +12*a(n-4) -12*a(n-5) -3*a(n-6) +6*a(n-7) -a(n-9) for n>19
EXAMPLE
Some solutions for n=4
..0..1..0..1. .0..0..1..0. .0..0..1..0. .0..0..1..0. .0..0..1..1
..0..1..0..0. .1..0..1..0. .1..1..0..1. .0..1..0..1. .1..0..0..1
..0..1..1..0. .1..0..1..1. .0..1..0..1. .0..1..0..1. .1..1..0..0
..0..0..0..1. .1..0..1..0. .0..1..0..1. .1..1..0..1. .0..1..1..1
..1..1..0..0. .0..1..0..1. .1..1..0..0. .0..1..0..1. .0..1..0..1
..0..1..1..0. .0..1..0..0. .0..1..1..0. .0..1..0..0. .0..1..1..1
CROSSREFS
Cf. A281056.
Sequence in context: A205415 A205408 A282116 * A270259 A205407 A045305
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 13 2017
STATUS
approved