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 A233176 Number of 3 X n 0..5 arrays with no element x(i,j) adjacent to itself or value 5-x(i,j) horizontally, diagonally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order (unlabelled 6-colorings with no clashing color pairs). 1

%I #7 Oct 10 2018 08:30:03

%S 11,80,2688,78336,2469888,76447744,2385772544,74291609600,

%T 2315406802944,72144847372288,2248141575290880,70053467808333824,

%U 2182930872087347200,68021929516908675072,2119621843032249204736,66049216835347669843968

%N Number of 3 X n 0..5 arrays with no element x(i,j) adjacent to itself or value 5-x(i,j) horizontally, diagonally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order (unlabelled 6-colorings with no clashing color pairs).

%H R. H. Hardin, <a href="/A233176/b233176.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 32*a(n-1) + 64*a(n-2) - 3072*a(n-3) + 8192*a(n-4) for n>5.

%F Empirical g.f.: x*(11 - 272*x - 576*x^2 + 20992*x^3 - 53248*x^4) / ((1 - 8*x)*(1 - 24*x - 256*x^2 + 1024*x^3)). - _Colin Barker_, Oct 10 2018

%e Some solutions for n=4:

%e ..0..1..0..4....0..1..5..2....0..1..0..2....0..1..0..1....0..1..2..1

%e ..5..1..5..2....5..1..0..4....3..1..5..1....2..1..5..4....5..1..0..4

%e ..0..4..5..2....3..1..0..4....2..1..5..1....5..1..0..1....5..4..5..1

%Y Row 3 of A233174.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 05 2013

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Last modified September 18 10:11 EDT 2024. Contains 375999 sequences. (Running on oeis4.)