A206652 Number of (n+2)X3 0..1 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly two ways, and new values 0..1 introduced in row major order

102, 390, 1517, 5805, 22346, 86251, 332419, 1281181, 4939106, 19039804, 73394261, 282923766, 1090629910, 4204204919, 16206551390, 62473746310, 240826563663, 928348880740, 3578640462085, 13795101927045, 53177970281187

Offset

1,1

Comments

Column 1 of A206659

Links

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

Formula

Empirical: a(n) = 5*a(n-2) +26*a(n-3) +42*a(n-4) +33*a(n-5) -28*a(n-6) -100*a(n-7) -102*a(n-8) -100*a(n-9) -122*a(n-10) -266*a(n-11) -194*a(n-12) -25*a(n-13) +279*a(n-14) +129*a(n-15) -147*a(n-16) -429*a(n-17) -379*a(n-18) -594*a(n-19) -576*a(n-20) -396*a(n-21) +452*a(n-22) +1179*a(n-23) +660*a(n-24) +391*a(n-25) -322*a(n-26) -54*a(n-27) +90*a(n-28)

Example

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

Crossrefs

Sequence in context: A277459 A127655 A206659 * A158127 A231361 A263117

Adjacent sequences: A206649 A206650 A206651 * A206653 A206654 A206655

Keyword

nonn

Author

R. H. Hardin Feb 11 2012

Status

approved