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A302473
Number of 3Xn 0..1 arrays with every element equal to 1, 2, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
2
0, 11, 49, 203, 955, 4556, 21843, 103319, 491073, 2332753, 11082938, 52648987, 250106679, 1188163911, 5644397853, 26814116700, 127381683511, 605134192403, 2874722191055, 13656526930929, 64876076932622, 308197362006435
OFFSET
1,2
COMMENTS
Row 3 of A302472.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +17*a(n-2) +15*a(n-3) -33*a(n-4) -62*a(n-5) -148*a(n-6) -116*a(n-7) +343*a(n-8) +429*a(n-9) +269*a(n-10) +191*a(n-11) -415*a(n-12) -534*a(n-13) -468*a(n-14) -436*a(n-15) -132*a(n-16) -72*a(n-17) -8*a(n-18) +8*a(n-19) for n>21
EXAMPLE
Some solutions for n=5
..0..0..1..1..1. .0..1..0..0..1. .0..0..0..1..1. .0..1..1..0..0
..1..1..0..0..0. .0..0..1..1..0. .0..0..1..0..1. .1..0..0..0..0
..1..0..0..1..1. .0..0..0..0..1. .1..1..1..0..0. .0..1..1..1..1
CROSSREFS
Cf. A302472.
Sequence in context: A295420 A003063 A124857 * A126398 A159486 A284857
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 08 2018
STATUS
approved