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A297583 Number of 2 X n 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 4 neighboring 1s. 1
1, 5, 11, 17, 39, 93, 183, 373, 823, 1741, 3599, 7637, 16247, 34125, 71871, 152133, 321127, 676861, 1429135, 3017909, 6367607, 13437869, 28367775, 59874021, 126360711, 266707549, 562939183, 1188130069, 2507681687, 5292853517 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) + 4*a(n-3) + 2*a(n-4).

Empirical g.f.: x*(1 + 4*x + 6*x^2 + 2*x^3) / (1 - x - 4*x^3 - 2*x^4). - Colin Barker, Mar 01 2019

EXAMPLE

Some solutions for n=7:

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

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

CROSSREFS

Row 2 of A297582.

Sequence in context: A277290 A085634 A157478 * A088903 A094205 A136091

Adjacent sequences:  A297580 A297581 A297582 * A297584 A297585 A297586

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 01 2018

STATUS

approved

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Last modified September 22 03:54 EDT 2020. Contains 337289 sequences. (Running on oeis4.)