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A318209
Number of nX3 0..1 arrays with every element unequal to 1, 2, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
1
1, 6, 4, 21, 47, 125, 329, 842, 2254, 5893, 15435, 40669, 106859, 280658, 738110, 1940361, 5099669, 13407853, 35248057, 92658886, 243597948, 640404049, 1683558645, 4425986909, 11635671179, 30589415206, 80417882852, 211414206553
OFFSET
1,2
COMMENTS
Column 3 of A318214.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +5*a(n-2) +6*a(n-3) -8*a(n-4) -32*a(n-5) -19*a(n-6) +17*a(n-7) +43*a(n-8) +36*a(n-9) +24*a(n-10) +8*a(n-11) -10*a(n-12) -66*a(n-13) -26*a(n-14) +28*a(n-15) +8*a(n-16) -20*a(n-17) -2*a(n-18) +46*a(n-19) -18*a(n-20) -44*a(n-21) +32*a(n-23) -5*a(n-24) -15*a(n-25) +13*a(n-26) +6*a(n-27) -8*a(n-28) -4*a(n-29) +5*a(n-30) +a(n-31) -a(n-32) for n>33
EXAMPLE
Some solutions for n=5
..0..0..1. .0..0..0. .0..1..0. .0..1..1. .0..1..1. .0..1..1. .0..1..0
..1..0..1. .1..0..1. .0..0..0. .0..1..0. .1..1..0. .1..0..0. .0..0..0
..0..1..0. .0..0..0. .0..1..0. .0..0..0. .1..1..1. .1..1..0. .0..1..1
..0..0..0. .1..0..0. .1..0..0. .0..1..0. .0..1..0. .1..0..0. .0..0..1
..0..1..0. .0..0..1. .1..1..1. .1..1..0. .1..1..1. .0..0..1. .1..1..0
CROSSREFS
Cf. A318214.
Sequence in context: A321417 A185734 A292696 * A120462 A236602 A169689
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 21 2018
STATUS
approved