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A299594 Number of n X 7 0..1 arrays with every element unequal to 0, 1 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 1
21, 26, 65, 250, 541, 1225, 2583, 5488, 11899, 25570, 54750, 117697, 252985, 543115, 1166472, 2505919, 5382274, 11560042, 24830445, 53333641, 114554095, 246050920, 528494067, 1135150426, 2438187262, 5236983073, 11248510665, 24160660963 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 7 of A299595.

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) +a(n-2) +3*a(n-3) +a(n-4) -a(n-5) -a(n-6) for n>9.

Empirical g.f.: x*(21 + 5*x + 18*x^2 + 96*x^3 + 127*x^4 + 234*x^5 + 49*x^6 - 102*x^7 - 73*x^8) / ((1 + x^2 - x^3)*(1 - x - 2*x^2 - x^3)). - Colin Barker, Feb 15 2018

EXAMPLE

Some solutions for n=5:

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

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

CROSSREFS

Cf. A299595.

Sequence in context: A035700 A134935 A344978 * A318544 A173836 A064507

Adjacent sequences:  A299591 A299592 A299593 * A299595 A299596 A299597

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 13 2018

STATUS

approved

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Last modified May 25 03:39 EDT 2022. Contains 354047 sequences. (Running on oeis4.)