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A301819 Number of nX4 0..1 arrays with every element equal to 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero. 1
2, 8, 25, 68, 177, 457, 1183, 3075, 8018, 20947, 54782, 143348, 375200, 982178, 2571247, 6731462, 17623023, 46137475, 120789253, 316230117, 827900912, 2167472413, 5674516100, 14856075638, 38893710542, 101825055692, 266581456213 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A301823.

LINKS

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

FORMULA

Empirical: a(n) = 6*a(n-1) -13*a(n-2) +13*a(n-3) -6*a(n-4) +a(n-5)

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A301823.

Sequence in context: A066455 A066374 A193048 * A119854 A176855 A309237

Adjacent sequences:  A301816 A301817 A301818 * A301820 A301821 A301822

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 27 2018

STATUS

approved

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Last modified October 20 22:44 EDT 2019. Contains 328291 sequences. (Running on oeis4.)