A204488 Number of (n+2)X6 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

1690, 2627, 5407, 11137, 22341, 44712, 90942, 187020, 388236, 811400, 1704979, 3596411, 7607012, 16120249, 34215382, 72726284, 154732914, 329467719, 702061540, 1496757080, 3192362462, 6811840986, 14538763224, 31037544146

Offset

1,1

Comments

Column 4 of A204492

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = a(n-1) +a(n-2) +9*a(n-3) -5*a(n-4) -10*a(n-5) -7*a(n-6) -26*a(n-7) +18*a(n-8) -13*a(n-9) +58*a(n-10) -4*a(n-11) +22*a(n-12) -26*a(n-13) -11*a(n-14) -16*a(n-15) +a(n-16) +6*a(n-17) +6*a(n-18) -3*a(n-19) for n>28

Example

Some solutions for n=3
..0..1..0..0..1..1....0..0..1..0..0..0....0..0..0..1..0..0....0..0..1..0..0..1
..0..0..1..0..0..1....0..1..0..1..1..0....0..1..0..0..1..1....0..1..1..0..1..0
..1..0..0..1..0..1....1..1..1..0..1..1....1..0..1..0..0..1....0..1..0..0..1..0
..0..1..0..0..1..0....1..0..0..0..1..0....1..0..0..1..0..0....0..0..1..0..0..1
..0..1..1..0..0..0....0..1..0..1..1..0....0..0..1..1..0..1....0..1..1..0..1..1

Crossrefs

Sequence in context: A281062 A020241 A065903 * A062680 A251291 A120564

Adjacent sequences: A204485 A204486 A204487 * A204489 A204490 A204491

Keyword

nonn

Author

R. H. Hardin Jan 15 2012

Status

approved