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A204486
Number of (n+2)X4 0..1 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly one way, and new values 0..1 introduced in row major order
1
214, 511, 1189, 2627, 5804, 12861, 28743, 64707, 146082, 330644, 750551, 1704263, 3871635, 8805671, 20024492, 45534930, 103602511, 235678796, 536072298, 1219716427, 2774892264, 6312360407, 14361996073, 32674647931, 74332115679
OFFSET
1,1
COMMENTS
Column 2 of A204492
LINKS
FORMULA
Empirical: a(n) = a(n-1) +a(n-2) +10*a(n-3) -6*a(n-4) -10*a(n-5) -17*a(n-6) -3*a(n-7) +23*a(n-8) -3*a(n-9) +37*a(n-10) -19*a(n-11) +26*a(n-12) -48*a(n-13) +4*a(n-14) -19*a(n-15) +21*a(n-16) +a(n-17) +4*a(n-18) -2*a(n-19) for n>29
EXAMPLE
Some solutions for n=3
..0..0..0..1....0..0..1..0....0..0..1..1....0..1..0..0....0..1..0..0
..1..1..0..1....0..1..0..1....0..1..0..1....0..0..1..1....1..1..1..0
..1..0..1..0....1..1..1..0....0..0..1..0....1..0..0..1....1..0..1..0
..1..0..0..0....0..0..1..1....1..1..0..1....1..1..0..0....0..1..0..1
..1..1..0..1....0..1..0..1....1..1..1..0....0..1..1..0....0..0..1..0
CROSSREFS
Sequence in context: A242804 A076159 A258961 * A221807 A200043 A184600
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 15 2012
STATUS
approved