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A317811 Number of nX4 0..1 arrays with every element unequal to 0, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 1
1, 3, 4, 7, 34, 56, 77, 228, 551, 1300, 3171, 6929, 16038, 38283, 89884, 210213, 489040, 1140562, 2668604, 6250857, 14610077, 34124180, 79756933, 186440331, 435962650, 1019155893, 2382147016, 5568392343, 13017040048, 30430709271, 71136801083 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 4 of A317815.

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +a(n-2) +a(n-3) -a(n-4) +8*a(n-5) -27*a(n-6) -20*a(n-7) -25*a(n-8) +70*a(n-9) +24*a(n-10) +124*a(n-11) +86*a(n-12) -80*a(n-13) -377*a(n-14) -343*a(n-15) -193*a(n-16) +448*a(n-17) +876*a(n-18) +779*a(n-19) -318*a(n-20) -936*a(n-21) -1187*a(n-22) -832*a(n-23) +863*a(n-24) +974*a(n-25) +1386*a(n-26) +118*a(n-27) -382*a(n-28) -1152*a(n-29) -661*a(n-30) +95*a(n-31) +336*a(n-32) +620*a(n-33) -201*a(n-34) +174*a(n-35) -269*a(n-36) +136*a(n-37) -152*a(n-38) +49*a(n-39) -76*a(n-40) +46*a(n-41) +11*a(n-42) -4*a(n-43) +16*a(n-44) -5*a(n-45) -a(n-48) for n>52

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A317815.

Sequence in context: A007677 A042773 A042173 * A046461 A084590 A279920

Adjacent sequences:  A317808 A317809 A317810 * A317812 A317813 A317814

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 07 2018

STATUS

approved

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Last modified April 26 04:11 EDT 2019. Contains 322469 sequences. (Running on oeis4.)