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A268780 Number of n X 7 binary arrays with some element plus some horizontally, vertically, diagonally or antidiagonally adjacent neighbor totalling two no more than once. 1

%I #6 May 04 2021 15:33:02

%S 72,766,10615,115391,1288693,13493468,140404442,1425678976,

%T 14341399141,142487073304,1404716302427,13742060955231,

%U 133640514636584,1292631496259982,12446235637750465,119353876258739189

%N Number of n X 7 binary arrays with some element plus some horizontally, vertically, diagonally or antidiagonally adjacent neighbor totalling two no more than once.

%C Column 7 of A268781.

%H R. H. Hardin, <a href="/A268780/b268780.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 12*a(n-1) +64*a(n-2) -942*a(n-3) -1476*a(n-4) +26868*a(n-5) +2249*a(n-6) -376788*a(n-7) +333472*a(n-8) +2686292*a(n-9) -4376424*a(n-10) -8985248*a(n-11) +21881197*a(n-12) +12658940*a(n-13) -55768960*a(n-14) +923990*a(n-15) +80699088*a(n-16) -25850884*a(n-17) -69171189*a(n-18) +34934900*a(n-19) +34833816*a(n-20) -22502076*a(n-21) -9502460*a(n-22) +7752808*a(n-23) +1023260*a(n-24) -1356480*a(n-25) +55136*a(n-26) +94080*a(n-27) -14400*a(n-28).

%e Some solutions for n=4

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

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

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

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

%Y Cf. A268781.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 13 2016

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Last modified April 25 07:07 EDT 2024. Contains 371964 sequences. (Running on oeis4.)