A204148 Number of (n+2)X5 0..2 arrays with every 3X3 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..2 introduced in row major order

22262, 156494, 844136, 4683434, 26968208, 152500334, 864266300, 4899355202, 27659513336, 156403395974, 885488808860, 5010133294922, 28351229796320, 160432064183822, 907680953036564, 5135781562487282, 29060183003735912

Offset

1,1

Comments

Column 3 of A204153

Links

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

Formula

Empirical: a(n) = 6*a(n-1) -5*a(n-2) +24*a(n-3) -90*a(n-4) +324*a(n-5) +678*a(n-6) -4752*a(n-7) -176*a(n-8) -2976*a(n-9) +29432*a(n-10) -1248*a(n-11) -59232*a(n-12) +123264*a(n-13) -85248*a(n-14) +193536*a(n-15) -525312*a(n-16) +331776*a(n-17) for n>18

Example

Some solutions for n=4
..0..0..1..2..2....0..1..1..2..0....0..0..0..1..1....0..0..1..2..0
..0..0..2..1..0....2..0..2..0..0....1..0..1..0..0....1..0..2..0..0
..1..2..0..2..1....0..2..0..2..1....1..1..0..1..0....2..2..0..2..2
..2..1..2..0..2....1..0..2..0..2....1..0..1..0..1....2..0..2..2..2
..1..2..1..2..0....1..1..0..2..0....0..1..0..1..2....0..2..2..2..1
..2..0..2..1..1....1..1..1..0..2....2..1..1..0..1....0..2..2..1..0

Crossrefs

Sequence in context: A217875 A253737 A185608 * A251825 A119568 A204333

Adjacent sequences: A204145 A204146 A204147 * A204149 A204150 A204151

Keyword

nonn

Author

R. H. Hardin Jan 11 2012

Status

approved