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A326160 Number of nX3 0..1 arrays with every element unequal to 0, 1, 3, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 1
3, 6, 9, 25, 60, 160, 396, 996, 2480, 6213, 15537, 38935, 97574, 244521, 612350, 1533665, 3841552, 9623474, 24106566, 60386058, 151263372, 378906980, 949140173, 2377551381, 5955661956, 14918670478, 37370561312, 93611479464, 234492365157 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A326165.

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-1) -5*a(n-2) -13*a(n-3) +38*a(n-4) -31*a(n-5) -41*a(n-6) +136*a(n-7) -125*a(n-8) -80*a(n-9) +370*a(n-10) -296*a(n-11) -270*a(n-12) +562*a(n-13) -178*a(n-14) -302*a(n-15) +321*a(n-16) -43*a(n-17) -63*a(n-18) +71*a(n-19) -103*a(n-20) +26*a(n-21) +54*a(n-22) -41*a(n-23) -a(n-24) +15*a(n-25) -5*a(n-26) -2*a(n-27) +a(n-28) for n>30

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A326165.

Sequence in context: A026095 A061929 A318032 * A301536 A296110 A019461

Adjacent sequences:  A326157 A326158 A326159 * A326161 A326162 A326163

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 09 2019

STATUS

approved

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Last modified August 7 15:08 EDT 2020. Contains 336276 sequences. (Running on oeis4.)