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A269030 Number of nX3 0..2 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once. 1
12, 48, 348, 2136, 12228, 67104, 357756, 1867560, 9593844, 48665904, 244357740, 1216672824, 6015296484, 29561944128, 144531868764, 703461546312, 3410368965588, 16475694411600, 79347347565132, 381071870841432 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A269035.

LINKS

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

FORMULA

Empirical: a(n) = 10*a(n-1) -29*a(n-2) +20*a(n-3) -4*a(n-4) for n>5

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Cf. A269035.

Sequence in context: A242026 A052601 A003498 * A222359 A002899 A222966

Adjacent sequences:  A269027 A269028 A269029 * A269031 A269032 A269033

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 18 2016

STATUS

approved

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Last modified February 17 17:27 EST 2018. Contains 299296 sequences. (Running on oeis4.)