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A202196 Number of (n+2) X 4 binary arrays avoiding patterns 001 and 101 in rows and columns. 1
240, 640, 1400, 2688, 4704, 7680, 11880, 17600, 25168, 34944, 47320, 62720, 81600, 104448, 131784, 164160, 202160, 246400, 297528, 356224, 423200, 499200, 585000, 681408, 789264, 909440, 1042840, 1190400, 1353088, 1531904, 1727880, 1942080 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A202202.

LINKS

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

FORMULA

Empirical: a(n) = 4*(n+4)*(n+3)*(n+2)^2/3.

Conjectures from Colin Barker, May 27 2018: (Start)

G.f.: 8*x*(30 - 70*x + 75*x^2 - 39*x^3 + 8*x^4) / (1 - x)^5.

a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.

(End)

EXAMPLE

Some solutions for n=6:

..0..1..1..1....1..1..1..1....1..1..1..0....1..1..1..1....1..1..1..1

..1..1..1..1....1..1..1..0....1..1..1..1....1..1..1..1....1..1..1..1

..1..1..1..1....1..1..0..0....1..1..1..0....0..1..1..1....1..1..1..1

..1..1..1..0....1..1..0..0....0..1..1..0....0..1..1..1....1..1..1..1

..1..1..1..0....1..1..0..0....0..1..1..0....0..1..1..1....1..1..1..1

..1..1..1..0....1..1..0..0....0..1..0..0....0..1..1..0....0..1..1..1

..1..1..0..0....1..1..0..0....0..0..0..0....0..1..1..0....0..1..1..0

..1..1..0..0....1..1..0..0....0..0..0..0....0..1..0..0....0..1..1..0

CROSSREFS

Cf. A202202.

Sequence in context: A119659 A263161 A268772 * A060663 A092000 A124352

Adjacent sequences:  A202193 A202194 A202195 * A202197 A202198 A202199

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 14 2011

STATUS

approved

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Last modified October 6 12:25 EDT 2022. Contains 357264 sequences. (Running on oeis4.)