A302872 - OEIS

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A302872

Number of nX3 0..1 arrays with every element equal to 0, 1, 3, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

3, 11, 17, 37, 82, 209, 536, 1549, 4513, 13980, 44424, 142457, 463592, 1518144, 4985864, 16423493, 54170895, 178797985, 590488247, 1950654770, 6444889749, 21296082916, 70373480203, 232558689443, 768538881502, 2539828012418

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Column 3 of A302877.

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) +9*a(n-3) -15*a(n-4) -5*a(n-5) -22*a(n-6) -7*a(n-7) +9*a(n-8) -32*a(n-9) -10*a(n-10) -16*a(n-11) -40*a(n-12) -16*a(n-13) for n>16

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A302877.

Sequence in context: A197225 A181507 A154934 * A023865 A024592 A203162

Adjacent sequences: A302869 A302870 A302871 * A302873 A302874 A302875

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 15 2018

STATUS

approved