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A226001 Number of pairs of orthogonal (-3,7) vectors of length 10*n. 2

%I

%S 8160,11670170880,13816736416550400,8837797610915077242880,

%T 7704457212444839067088322560,7041012236359757418211467425218560,

%U 6005570486226633002683450297283300556800

%N Number of pairs of orthogonal (-3,7) vectors of length 10*n.

%C Row 15 of A225987.

%H R. H. Hardin, <a href="/A226001/b226001.txt">Table of n, a(n) for n = 1..45</a>

%e Some solutions for n=1

%e .-3..7...-3..7...-3..7....7..7....7..7...-3..7....7..7...-3..7...-3.-3....7..7

%e .-3..7....7.-3....7.-3...-3..7...-3..7....7..7...-3..7...-3..7...-3..7...-3..7

%e ..7.-3....7..7....7.-3....7..7....7.-3....7.-3...-3..7....7..7...-3.-3....7..7

%e ..7.-3...-3..7...-3..7...-3..7...-3..7...-3..7...-3..7....7..7...-3.-3....7.-3

%e ..7.-3....7.-3...-3..7....7..7....7..7...-3..7....7.-3....7.-3...-3.-3....7.-3

%e .-3..7...-3..7....7.-3...-3..7...-3..7....7..7....7..7....7.-3...-3..7....7..7

%e ..7..7....7..7....7..7...-3..7....7.-3....7.-3....7.-3...-3..7...-3.-3....7.-3

%e ..7..7...-3..7....7..7....7.-3....7..7....7..7...-3..7....7.-3...-3.-3...-3..7

%e ..7..7...-3..7....7..7...-3..7...-3..7...-3..7....7.-3...-3..7...-3.-3....7.-3

%e ..7.-3....7..7...-3..7....7.-3...-3..7....7.-3....7..7....7..7...-3..7....7.-3

%K nonn

%O 1,1

%A _R. H. Hardin_, May 22 2013

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Last modified May 24 21:58 EDT 2022. Contains 354043 sequences. (Running on oeis4.)