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A204193
Number of nX4 0..1 arrays with no occurrence of three equal elements in a row horizontally, vertically or nw-to-se diagonally, and new values 0..1 introduced in row major order
1
5, 50, 86, 265, 883, 2974, 9940, 33462, 112470, 377908, 1270638, 4271547, 14358358, 48270403, 162269445, 545492694, 1833790077, 6164622703, 20723502506, 69666040146, 234195417025, 787291729779, 2646629705960, 8897142589375
OFFSET
1,1
COMMENTS
Column 4 of A204197
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +7*a(n-2) +a(n-3) -28*a(n-4) -30*a(n-5) +56*a(n-6) +71*a(n-7) -64*a(n-8) -74*a(n-9) +42*a(n-10) +39*a(n-11) -18*a(n-12) -9*a(n-13) +6*a(n-14) +a(n-15) -a(n-16) for n>19
EXAMPLE
Some solutions for n=5
..0..0..1..1....0..1..0..0....0..1..0..0....0..1..0..0....0..0..1..1
..0..1..0..0....0..1..0..0....1..0..1..1....1..1..0..1....0..1..0..0
..1..1..0..1....1..0..1..1....1..0..1..0....0..0..1..1....1..1..0..1
..1..0..1..1....0..0..1..0....0..1..0..0....1..1..0..0....1..0..1..0
..0..1..1..0....0..1..0..0....1..1..0..1....0..1..0..1....0..1..0..0
CROSSREFS
Sequence in context: A169964 A061474 A136916 * A136919 A136920 A358686
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 12 2012
STATUS
approved