A300677 - OEIS

A300677

Number of nX3 0..1 arrays with every element equal to 0, 2, 3 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

1, 2, 5, 11, 8, 58, 131, 306, 936, 2435, 6683, 18093, 49663, 134666, 367314, 1002020, 2728817, 7439403, 20275261, 55264984, 150614904, 410527337, 1118909399, 3049617734, 8311952136, 22654640136, 61746476769, 168293237171, 458692748831

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OFFSET

1,2

COMMENTS

Column 3 of A300682.

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-2) +9*a(n-3) +9*a(n-4) +3*a(n-5) -8*a(n-6) -a(n-7) -18*a(n-8) -24*a(n-9) -45*a(n-10) -10*a(n-11) -15*a(n-12) +39*a(n-13) -21*a(n-14) +9*a(n-15) -7*a(n-16) -13*a(n-17) +14*a(n-18) -5*a(n-19) +3*a(n-20) -2*a(n-22) +a(n-23) for n>26

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A300682.

Sequence in context: A357588 A276736 A069162 * A079008 A144573 A062251

Adjacent sequences: A300674 A300675 A300676 * A300678 A300679 A300680

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 11 2018

STATUS

approved