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A268806 Number of nX5 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once. 1

%I #4 Feb 13 2016 18:21:19

%S 144,772,4158,28452,195384,1316226,8734264,57302798,372342650,

%T 2400532536,15373692036,97900054556,620374078660,3914367133320,

%U 24605301916568,154148669247610,962830699411796,5997782979007294,37271323919688010

%N Number of nX5 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

%C Column 5 of A268809.

%H R. H. Hardin, <a href="/A268806/b268806.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +41*a(n-2) +54*a(n-3) -509*a(n-4) -2182*a(n-5) -2830*a(n-6) +1766*a(n-7) +7914*a(n-8) +2584*a(n-9) -10583*a(n-10) -6092*a(n-11) +11506*a(n-12) +5348*a(n-13) -11688*a(n-14) -620*a(n-15) +9251*a(n-16) -4462*a(n-17) -3137*a(n-18) +4774*a(n-19) -2365*a(n-20) +338*a(n-21) +198*a(n-22) -106*a(n-23) +12*a(n-24) +4*a(n-25) -a(n-26) for n>29

%e Some solutions for n=4

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

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

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

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

%Y Cf. A268809.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 13 2016

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Last modified April 23 15:20 EDT 2024. Contains 371916 sequences. (Running on oeis4.)