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A297514 Number of n X 3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 3 neighboring 1s. 1
3, 17, 49, 177, 727, 2445, 8931, 33841, 120079, 438161, 1618767, 5849585, 21333063, 78146401, 284124279, 1036090465, 3784306647, 13787045553, 50277043559, 183451730433, 668806025271, 2438991559953, 8896352148007, 32440479868961 (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) = a(n-1) + 2*a(n-2) + 30*a(n-3) + 6*a(n-5) - 124*a(n-6) - 8*a(n-8) + 64*a(n-9).

Empirical g.f.: x*(3 + 14*x + 26*x^2 + 4*x^3 - 58*x^4 - 124*x^5 - 8*x^6 + 24*x^7 + 64*x^8) / (1 - x - 2*x^2 - 30*x^3 - 6*x^5 + 124*x^6 + 8*x^8 - 64*x^9). - Colin Barker, Feb 28 2019

EXAMPLE

Some solutions for n=7:

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

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

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

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

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

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

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

CROSSREFS

Column 3 of A297519.

Sequence in context: A154304 A144640 A084069 * A307862 A132124 A011917

Adjacent sequences:  A297511 A297512 A297513 * A297515 A297516 A297517

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 31 2017

STATUS

approved

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Last modified October 14 16:48 EDT 2019. Contains 328022 sequences. (Running on oeis4.)