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A211693 Number of -4..4 arrays x(i) of n+1 elements i=1..n+1 with x(i)+x(j), x(i+1)+x(j+1), -(x(i)+x(j+1)), and -(x(i+1)+x(j)) having two, three or four distinct values for every i<=n and j<=n 1

%I

%S 80,712,6328,56184,498328,4415576,39087704,345688344,3054441560,

%T 26964466456,237834515800,2095997626392,18456488165848,

%U 162389882849432,1427675316724184,12542069778534552,110099840447243864

%N Number of -4..4 arrays x(i) of n+1 elements i=1..n+1 with x(i)+x(j), x(i+1)+x(j+1), -(x(i)+x(j+1)), and -(x(i+1)+x(j)) having two, three or four distinct values for every i<=n and j<=n

%H R. H. Hardin, <a href="/A211693/b211693.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 40*a(n-1) -630*a(n-2) +4800*a(n-3) -16675*a(n-4) +13128*a(n-5) +34290*a(n-6) +17120*a(n-7) +3176*a(n-8) +192*a(n-9)

%e Some solutions for n=5

%e .-4...-1...-3...-4...-3...-1...-3...-3...-4...-1...-2...-2...-1...-4...-4...-4

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

%e .-3...-2...-2...-2...-1...-1...-2...-4...-4...-2...-4...-4...-4...-3...-2...-2

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Apr 18 2012

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Last modified October 5 10:54 EDT 2022. Contains 357255 sequences. (Running on oeis4.)