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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 1
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified January 26 13:42 EST 2022. Contains 350598 sequences. (Running on oeis4.)