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A268901 Number of n X 5 0..2 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once. 1
96, 2664, 54936, 1004184, 17194680, 282550680, 4513169016, 70609114584, 1087342615224, 16536864398616, 248976164499192, 3717450986032728, 55118358414612792, 812385229848253848, 11912420604393611640 (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) = 30*a(n-1) - 261*a(n-2) + 540*a(n-3) - 324*a(n-4).

Empirical g.f.: 24*x*(4 - 9*x + 3*x^2 - 18*x^3) / (1 - 15*x + 18*x^2)^2. - Colin Barker, Jan 16 2019

EXAMPLE

Some solutions for n=3:

..1..2..2..1..2. .2..2..1..0..1. .2..1..0..1..2. .0..1..2..2..1

..2..2..2..1..0. .2..0..1..0..1. .2..1..0..0..0. .0..1..2..1..0

..2..2..0..0..0. .1..0..1..0..0. .0..1..0..0..0. .2..2..2..1..0

CROSSREFS

Column 5 of A268904.

Sequence in context: A090449 A336677 A233709 * A239158 A105254 A234075

Adjacent sequences:  A268898 A268899 A268900 * A268902 A268903 A268904

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 15 2016

STATUS

approved

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Last modified October 3 18:24 EDT 2022. Contains 357237 sequences. (Running on oeis4.)