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A204392 Number of (n+2) X 4 0..1 arrays with no 3 X 3 subblock having three equal diagonal elements or three equal antidiagonal elements, and new values 0..1 introduced in row major order. 1
648, 4050, 27378, 175232, 1131008, 7311488, 47258642, 305390898, 1973176200, 12751406208, 82400136968, 532464529058, 3440804225762, 22234526147072, 143679727411200, 928460232000000, 5999721595740450, 38770275955862882 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 2 of A204398.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +15*a(n-2) +89*a(n-3) +211*a(n-4) +375*a(n-5) +149*a(n-6) -29*a(n-7) -195*a(n-8) -61*a(n-9) +61*a(n-10) +195*a(n-11) +29*a(n-12) -149*a(n-13) -375*a(n-14) -211*a(n-15) -89*a(n-16) -15*a(n-17) -a(n-18) +a(n-19).
EXAMPLE
Some solutions for n=3
..0..0..1..1....0..0..1..1....0..1..1..1....0..1..0..0....0..1..1..0
..1..1..0..1....0..0..0..0....1..0..0..0....1..0..1..0....1..1..0..1
..0..1..1..1....1..0..1..1....0..1..1..0....1..1..1..0....0..1..0..0
..0..0..0..0....1..1..1..1....0..1..0..0....0..1..0..1....0..1..0..0
..0..0..1..1....0..0..0..1....0..1..0..0....0..1..0..0....0..1..0..1
CROSSREFS
Cf. A204398.
Sequence in context: A171606 A006914 A337313 * A233677 A200938 A165611
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 15 2012
STATUS
approved

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Last modified February 20 21:52 EST 2024. Contains 370219 sequences. (Running on oeis4.)