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 A268885 Number of nX7 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once. 1

%I

%S 38,1340,42362,1187838,31427480,800733668,19876401224,483987898760,

%T 11611969197776,275345016177616,6466964539799840,150689548401385312,

%U 3487912674084234304,80273121207141357120,1838370376874099584640

%N Number of nX7 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

%C Column 7 of A268886.

%H R. H. Hardin, <a href="/A268885/b268885.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 68*a(n-1) -1804*a(n-2) +24560*a(n-3) -195400*a(n-4) +974752*a(n-5) -3171360*a(n-6) +6871936*a(n-7) -9999248*a(n-8) +9740096*a(n-9) -6250176*a(n-10) +2552576*a(n-11) -621824*a(n-12) +79872*a(n-13) -4096*a(n-14) for n>16

%e Some solutions for n=3

%e ..1..0..0..0..0..0..0. .0..0..0..1..0..1..0. .0..0..0..1..0..1..1

%e ..0..1..1..0..0..0..0. .1..1..0..1..0..1..0. .1..0..0..0..0..0..0

%e ..0..0..0..1..0..0..1. .0..1..0..0..0..0..0. .0..0..0..0..0..0..0

%Y Cf. A268886.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 15 2016

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Last modified January 25 22:06 EST 2022. Contains 350572 sequences. (Running on oeis4.)