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A209781
Half the number of (n+1)X3 0..3 arrays with every 2X2 subblock having exactly one duplicate clockwise edge difference
1
576, 12492, 266126, 5719838, 122871278, 2641341716, 56780957220, 1220714555712, 26243950399348, 564220215862026, 12130228710486118, 260789425643620742, 5606749493903244274, 120540344808285189504, 2591515087636992673274
OFFSET
1,1
COMMENTS
Column 2 of A209787
LINKS
FORMULA
Empirical: a(n) = 32*a(n-1) -181*a(n-2) -1612*a(n-3) +14245*a(n-4) +3934*a(n-5) -228072*a(n-6) +286957*a(n-7) +1135539*a(n-8) -2087315*a(n-9) -2118396*a(n-10) +5249880*a(n-11) +1194011*a(n-12) -5705343*a(n-13) +530140*a(n-14) +2648017*a(n-15) -619565*a(n-16) -439672*a(n-17) +116050*a(n-18) +17928*a(n-19) -3952*a(n-20)
EXAMPLE
Some solutions for n=4
..1..1..2....2..2..0....0..1..0....1..0..0....0..3..0....2..0..2....1..1..3
..0..2..2....2..0..0....2..1..2....0..0..3....0..3..3....2..1..1....2..1..1
..1..1..3....0..0..1....1..1..0....1..2..1....2..1..1....3..3..2....1..1..3
..2..2..2....2..2..1....3..1..1....0..2..3....0..1..0....0..3..3....2..3..3
..2..1..1....0..0..3....0..2..3....1..1..3....2..2..2....3..3..1....1..3..1
CROSSREFS
Sequence in context: A235738 A236078 A264524 * A330840 A226285 A370226
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 13 2012
STATUS
approved