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A299591 Number of n X 4 0..1 arrays with every element unequal to 0, 1 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 1
5, 5, 11, 23, 53, 121, 250, 533, 1162, 2490, 5327, 11465, 24641, 52882, 113593, 244046, 524134, 1125735, 2418077, 5193785, 11155562, 23961133, 51466258, 110544050, 237437407, 509992017, 1095411137, 2352832034, 5053646321, 10854722326 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 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*(5 + x^2 - 8*x^3 - x^4 + 12*x^5 + 6*x^6 - 4*x^7 - 3*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..0. .0..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..1..0

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

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

CROSSREFS

Cf. A299595.

Sequence in context: A301800 A214827 A298955 * A350920 A173316 A242325

Adjacent sequences:  A299588 A299589 A299590 * A299592 A299593 A299594

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 13 2018

STATUS

approved

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Last modified June 25 07:37 EDT 2022. Contains 354835 sequences. (Running on oeis4.)