A204747 Number of (n+2)X3 0..1 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly three ways, and new values 0..1 introduced in row major order

40, 61, 102, 188, 342, 590, 1051, 1915, 3308, 5967, 10934, 19151, 34428, 62824, 110673, 199296, 363428, 644246, 1160545, 2112996, 3762407, 6782539, 12337147, 22050535, 39775619, 72285932, 129577181, 233878451, 424749674, 763172996

Offset

1,1

Comments

Column 1 of A204754

Links

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

Formula

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

Example

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

Crossrefs

Sequence in context: A195571 A060672 A204754 * A205066 A232870 A338373

Adjacent sequences: A204744 A204745 A204746 * A204748 A204749 A204750

Keyword

nonn

Author

R. H. Hardin Jan 18 2012

Status

approved