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A202195 Number of (n+2) X 3 binary arrays avoiding patterns 001 and 101 in rows and columns. 2
108, 240, 450, 756, 1176, 1728, 2430, 3300, 4356, 5616, 7098, 8820, 10800, 13056, 15606, 18468, 21660, 25200, 29106, 33396, 38088, 43200, 48750, 54756, 61236, 68208, 75690, 83700, 92256, 101376, 111078, 121380, 132300, 143856, 156066, 168948 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A202202.

LINKS

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

FORMULA

Empirical: a(n) = 3*(n+3)*(n+2)^2 = 3*A011379(n+2).

Conjectures from Colin Barker, Mar 03 2018: (Start)

G.f.: 6*x*(18 - 32*x + 23*x^2 - 6*x^3) / (1 - x)^4.

a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n>4.

(End)

EXAMPLE

Some solutions for n=10:

  0 0 0    0 0 0    1 0 0    1 0 0    1 0 0    0 1 1    0 1 1

  1 1 1    0 1 1    0 1 1    1 1 0    1 1 1    1 1 1    1 1 1

  1 1 0    0 1 1    0 1 1    0 1 0    1 1 1    1 1 1    1 1 1

  1 1 0    0 1 1    0 1 1    0 1 0    1 1 0    1 1 1    1 1 1

  1 1 0    0 1 1    0 1 0    0 1 0    1 0 0    1 1 1    1 1 1

  0 1 0    0 1 1    0 0 0    0 1 0    0 0 0    1 1 1    1 1 0

  0 1 0    0 1 1    0 0 0    0 1 0    0 0 0    1 1 0    1 0 0

  0 1 0    0 1 1    0 0 0    0 0 0    0 0 0    1 1 0    0 0 0

  0 1 0    0 1 0    0 0 0    0 0 0    0 0 0    0 1 0    0 0 0

  0 1 0    0 1 0    0 0 0    0 0 0    0 0 0    0 1 0    0 0 0

  0 1 0    0 0 0    0 0 0    0 0 0    0 0 0    0 0 0    0 0 0

  0 0 0    0 0 0    0 0 0    0 0 0    0 0 0    0 0 0    0 0 0

CROSSREFS

Cf. A202202.

Sequence in context: A275996 A235292 A202202 * A242867 A255091 A255084

Adjacent sequences:  A202192 A202193 A202194 * A202196 A202197 A202198

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 14 2011

STATUS

approved

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Last modified September 20 00:29 EDT 2020. Contains 337215 sequences. (Running on oeis4.)