A204491 Number of (n+2)X9 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

35172, 28743, 50897, 90942, 168567, 331723, 658793, 1277695, 2455575, 4765823, 9372187, 18590575, 37054835, 74180927, 148918284, 299395145, 602639784, 1214402311, 2449573637, 4945318628, 9990612579, 20196844929, 40859216212

Offset

1,1

Comments

Column 7 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) -28*a(n-7) +16*a(n-8) -9*a(n-9) +34*a(n-10) +3*a(n-11) +4*a(n-12) +26*a(n-13) -13*a(n-14) +14*a(n-15) -26*a(n-16) -3*a(n-17) -10*a(n-18) -2*a(n-19) +6*a(n-20) -6*a(n-21) +3*a(n-22) +6*a(n-24) -3*a(n-25) for n>37

Example

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

Crossrefs

Sequence in context: A234988 A075831 A213805 * A085545 A031855 A186567

Adjacent sequences: A204488 A204489 A204490 * A204492 A204493 A204494

Keyword

nonn

Author

R. H. Hardin Jan 15 2012

Status

approved