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Number of nX7 0..2 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.
1

%I #4 Feb 16 2016 13:46:17

%S 768,40176,1770048,72081792,2799406656,105294777120,3870355944960,

%T 139818682627488,4983158127443904,175684152567641184,

%U 6139001133769997952,212930705454132284064,7339160588604264574272,251599271436625798745568

%N Number of nX7 0..2 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.

%C Column 7 of A268971.

%H R. H. Hardin, <a href="/A268970/b268970.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 84*a(n-1) -2466*a(n-2) +31428*a(n-3) -206469*a(n-4) +750384*a(n-5) -1513404*a(n-6) +1574640*a(n-7) -656100*a(n-8)

%e Some solutions for n=2

%e ..2..2..1..0..1..2..2. .1..2..0..1..0..0..0. .0..1..2..1..0..1..0

%e ..1..0..1..2..1..2..0. .2..1..0..0..0..0..0. .2..1..2..1..2..0..1

%Y Cf. A268971.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 16 2016