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A231765 Number of (1+1) X (n+1) 0..1 arrays with no element having a strict majority of its horizontal, diagonal and antidiagonal neighbors equal to one. 1
9, 33, 100, 315, 961, 3024, 9409, 29319, 91204, 284279, 885481, 2758192, 8590761, 26760591, 83356900, 259648623, 808776721, 2519272112, 7847302225, 24443615655, 76139572356, 237167776135, 738755721081, 2301155717168, 7167887098681 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) + a(n-3) + 7*a(n-4) - 20*a(n-5) - 2*a(n-6) - 4*a(n-8) + 8*a(n-9).

Empirical g.f.: x*(9 + 6*x + x^2 + 6*x^3 - 80*x^4 - 10*x^5 - 8*x^7 + 32*x^8) / ((1 - 3*x - x^2 + 2*x^3)*(1 + x^2 - 6*x^4 - 4*x^6)). - Colin Barker, Oct 01 2018

EXAMPLE

Some solutions for n=7:

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

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

CROSSREFS

Row 1 of A231764.

Sequence in context: A112888 A048479 A031880 * A220165 A036543 A147269

Adjacent sequences:  A231762 A231763 A231764 * A231766 A231767 A231768

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 13 2013

STATUS

approved

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Last modified November 16 21:40 EST 2018. Contains 317275 sequences. (Running on oeis4.)