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A304699
Number of nX3 0..1 arrays with every element unequal to 1, 2, 4, 5 or 6 king-move adjacent elements, with upper left element zero.
1
1, 11, 8, 21, 46, 103, 201, 512, 1123, 2536, 6010, 14033, 32343, 76620, 180379, 423657, 1000938, 2367196, 5593222, 13232605, 31329142, 74187004, 175694455, 416223934, 986251748, 2337014644, 5538273336, 13126126679, 31110785899, 73739138697
OFFSET
1,2
COMMENTS
Column 3 of A304704.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +2*a(n-2) +10*a(n-3) -a(n-4) -20*a(n-5) -48*a(n-6) -31*a(n-7) +56*a(n-8) +107*a(n-9) +109*a(n-10) -30*a(n-11) -92*a(n-12) -70*a(n-13) -9*a(n-14) -35*a(n-15) -32*a(n-16) -4*a(n-17) for n>20
EXAMPLE
Some solutions for n=5
..0..1..1. .0..0..1. .0..1..0. .0..1..0. .0..1..1. .0..1..1. .0..1..1
..0..0..0. .1..1..1. .1..0..0. .0..1..0. .1..0..1. .0..0..0. .1..0..1
..0..1..1. .0..0..1. .0..0..0. .1..1..1. .0..0..1. .0..0..0. .1..1..0
..0..1..1. .0..0..1. .0..0..1. .1..1..1. .0..1..1. .1..0..1. .1..0..0
..0..0..0. .1..1..1. .0..1..0. .1..0..1. .1..0..1. .1..0..1. .0..1..0
CROSSREFS
Cf. A304704.
Sequence in context: A068974 A244447 A206420 * A377042 A133236 A038322
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 17 2018
STATUS
approved