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A318012 Number of nX4 0..1 arrays with every element unequal to 0, 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 1
8, 97, 508, 3062, 17703, 103633, 603215, 3512154, 20446744, 119050218, 693180972, 4036155290, 23501168666, 136839336291, 796768793476, 4639312324422, 27013128767994, 157288207910023, 915835429361804, 5332596422248712 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A318016.

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-1) +10*a(n-2) -30*a(n-3) -17*a(n-4) +84*a(n-5) +19*a(n-6) +24*a(n-7) +14*a(n-8) -490*a(n-9) -213*a(n-10) +715*a(n-11) +303*a(n-12) -544*a(n-13) -269*a(n-14) -82*a(n-15) -439*a(n-16) +318*a(n-17) +647*a(n-18) +21*a(n-19) -71*a(n-20) -24*a(n-21) -90*a(n-22) -21*a(n-23) +20*a(n-24) +4*a(n-25) -a(n-26) for n>29

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A318016.

Sequence in context: A300474 A317005 A002506 * A320398 A218451 A262777

Adjacent sequences:  A318009 A318010 A318011 * A318013 A318014 A318015

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 12 2018

STATUS

approved

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Last modified May 30 15:01 EDT 2020. Contains 334726 sequences. (Running on oeis4.)