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A207405
Number of 5Xn 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 1 0 vertically
1
10, 100, 390, 1521, 4212, 11664, 26676, 61009, 123006, 248004, 456666, 840889, 1445192, 2483776, 4042440, 6579225, 10244610, 15952036, 23944030, 35940025, 52300380, 76108176, 107854812, 152843769, 211679286, 293162884, 397932402
OFFSET
1,1
COMMENTS
Row 5 of A207403
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +8*a(n-2) -18*a(n-3) -27*a(n-4) +72*a(n-5) +48*a(n-6) -168*a(n-7) -42*a(n-8) +252*a(n-9) -252*a(n-11) +42*a(n-12) +168*a(n-13) -48*a(n-14) -72*a(n-15) +27*a(n-16) +18*a(n-17) -8*a(n-18) -2*a(n-19) +a(n-20)
EXAMPLE
Some solutions for n=4
..0..0..0..0....1..1..0..0....0..0..0..0....1..0..1..0....1..1..0..0
..1..0..0..0....0..0..0..0....0..1..0..0....0..1..0..0....1..1..1..0
..0..0..0..0....1..0..0..0....0..0..0..0....0..1..0..0....1..1..1..0
..0..0..0..0....0..0..0..0....0..0..0..0....0..1..0..0....1..1..1..0
..0..0..0..0....0..0..0..0....0..0..0..0....0..1..0..0....1..1..1..0
CROSSREFS
Sequence in context: A086115 A209652 A207072 * A207706 A207251 A208289
KEYWORD
nonn
AUTHOR
R. H. Hardin Feb 17 2012
STATUS
approved