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A280438 Number of n X 6 0..1 arrays with no element equal to more than one of its horizontal and vertical neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards. 1
10, 68, 136, 232, 360, 548, 834, 1284, 2008, 3188, 5128, 8332, 13638, 22436, 37032, 61248, 101416, 168020, 278410, 461284, 764088, 1265228, 2094216, 3464892, 5730190, 9472388, 15651784, 25851544, 42680808, 70438148, 116203218, 191632452 (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) = 4*a(n-1) - 4*a(n-2) - 2*a(n-3) + 4*a(n-4) - a(n-6) for n>7.

Empirical g.f.: 2*x*(5 + 14*x - 48*x^2 - 10*x^3 + 36*x^4 + 18*x^5 + 6*x^6) / ((1 - x)^2*(1 - x - x^2)^2). - Colin Barker, Feb 13 2019

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Column 6 of A280440.

Sequence in context: A197783 A197751 A144052 * A192021 A026984 A104598

Adjacent sequences:  A280435 A280436 A280437 * A280439 A280440 A280441

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 03 2017

STATUS

approved

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Last modified January 28 13:29 EST 2020. Contains 331321 sequences. (Running on oeis4.)