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A301660
Number of nX6 0..1 arrays with every element equal to 0, 1 or 4 horizontally or vertically adjacent elements, with upper left element zero.
1
13, 14, 26, 45, 99, 254, 696, 2013, 5953, 17878, 54126, 164525, 501455, 1530694, 4676360, 14293737, 43703389, 133647942, 408746766, 1250182369, 3823920719, 11696450282, 35777089740, 109435800649, 334746407201, 1023938030574
OFFSET
1,1
COMMENTS
Column 6 of A301662.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) -2*a(n-2) +2*a(n-3) -14*a(n-4) -7*a(n-5) +3*a(n-6) +44*a(n-7) +22*a(n-8) -28*a(n-9) -45*a(n-10) -15*a(n-11) +25*a(n-12) +22*a(n-13) +2*a(n-14) -11*a(n-15) -4*a(n-16) +a(n-17) +2*a(n-18)
EXAMPLE
Some solutions for n=5
..0..1..0..1..0..1. .0..1..0..1..0..1. .0..1..0..1..0..1. .0..1..0..1..0..1
..0..1..0..1..0..1. .1..1..1..0..1..0. .1..0..1..1..1..0. .1..0..1..1..1..0
..1..0..1..0..1..0. .0..1..0..1..0..1. .0..1..0..1..0..1. .0..1..0..1..0..1
..0..1..0..1..1..1. .1..0..0..0..1..0. .1..1..1..0..1..0. .1..0..0..0..1..0
..1..0..1..0..1..0. .0..1..0..1..0..1. .0..1..0..1..0..1. .0..1..0..1..0..1
CROSSREFS
Cf. A301662.
Sequence in context: A079831 A022803 A112653 * A022103 A224224 A041342
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 25 2018
STATUS
approved