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A300493 Number of nX3 0..1 arrays with every element equal to 0, 1, 2 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 2
4, 18, 52, 143, 412, 1225, 3699, 11243, 34012, 102446, 307967, 926094, 2787783, 8398551, 25307489, 76250370, 229695945, 691863018, 2083934202, 6277172983, 18908580942, 56958622146, 171576895601, 516838549210, 1556857505073 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A300498.

LINKS

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

FORMULA

Empirical: a(n) = 7*a(n-1) -17*a(n-2) +12*a(n-3) +23*a(n-4) -46*a(n-5) +4*a(n-6) +24*a(n-7) +20*a(n-8) -52*a(n-9) +5*a(n-10) +53*a(n-11) +22*a(n-12) -47*a(n-13) -86*a(n-14) +78*a(n-15) +89*a(n-16) +84*a(n-17) -64*a(n-18) -22*a(n-19) -35*a(n-20) +15*a(n-21) +a(n-22) +4*a(n-23) -a(n-24) for n>25

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A300498.

Sequence in context: A092349 A027659 A059133 * A300876 A301486 A284607

Adjacent sequences:  A300490 A300491 A300492 * A300494 A300495 A300496

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 07 2018

STATUS

approved

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Last modified May 26 22:57 EDT 2019. Contains 323597 sequences. (Running on oeis4.)