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A299677
Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 4, 5, 6 or 7 king-move adjacent elements, with upper left element zero.
1
4, 13, 20, 45, 147, 506, 1561, 5017, 16429, 53365, 172859, 562276, 1828820, 5943264, 19318649, 62811656, 204197935, 663816782, 2158064264, 7015860029, 22808258862, 74148897744, 241056311862, 783667226084, 2547678766746, 8282432122501
OFFSET
1,1
COMMENTS
Column 3 of A299682.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) -2*a(n-2) +4*a(n-3) -16*a(n-4) -13*a(n-5) +12*a(n-6) +40*a(n-7) +23*a(n-8) -37*a(n-9) +15*a(n-10) -88*a(n-11) +52*a(n-12) -48*a(n-13) +49*a(n-14) -8*a(n-15) +20*a(n-16) for n>17
EXAMPLE
Some solutions for n=5
..0..0..1. .0..0..1. .0..1..0. .0..1..0. .0..1..0. .0..1..0. .0..0..1
..0..1..1. .1..1..0. .0..1..1. .0..1..0. .0..0..0. .1..0..1. .1..1..1
..0..0..0. .0..1..1. .1..1..1. .0..1..0. .0..0..0. .0..0..1. .0..1..1
..0..0..1. .0..1..1. .0..0..1. .0..1..0. .1..0..0. .0..0..1. .0..1..1
..0..1..1. .1..0..1. .0..1..1. .0..1..0. .1..1..0. .1..0..1. .0..1..0
CROSSREFS
Cf. A299682.
Sequence in context: A299874 A299010 A299801 * A300309 A228138 A339271
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 16 2018
STATUS
approved