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A085799
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Determinant of the symmetric n X n matrix A defined by A[i,j] = |i^2-j^2| for 1 <= i,j <= n.
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0
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0, -9, 240, -6300, 181440, -5821200, 207567360, -8172964800, 352864512000, -16593453676800, 844757641728000, -46306798060723200, 2720119606364160000, -170493211041753600000, 11359219476176732160000
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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EXAMPLE
| Contribution from Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Apr 28 2010: (Start)
a(5) = determinant(A) = 181440 where A is the matrix
[ 0 3 8 15 24]
[ 3 0 5 12 21]
[ 8 5 0 7 16]
[15 12 7 0 9]
[24 21 16 9 0] (End)
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MAPLE
| (Conjectured to give the same sequence, apart from signs): a:=n->sum((count(Permutation(n*2-1), size=n+1)), j=0..n)/2: seq(a(n), n=1..16); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 03 2007
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MATHEMATICA
| A[i_, j_] := Abs[i^2 - j^2]; a[n_] := Det[Table[A[i, j], {i, n}, {j, n}]]; Table[a[n], {n, 44}] - J. M. Grau Ribas (grau(AT)uniovi.es), Apr 17 2010
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PROG
| (MAGMA) [ Determinant( SymmetricMatrix( &cat[ [ Abs(i^2-j^2): j in [1..i] ]: i in [1..n] ] ) ): n in [1..15] ]; [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Apr 28 2010]
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CROSSREFS
| Cf. A085750.
Sequence in context: A165389 A153223 A157569 * A183903 A075127 A013733
Adjacent sequences: A085796 A085797 A085798 * A085800 A085801 A085802
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KEYWORD
| sign
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AUTHOR
| Yuval Dekel (dekelyuval(AT)hotmail.com), Jul 24 2003
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EXTENSIONS
| More terms from J. M. Grau Ribas (grau(AT)uniovi.es), Apr 17 2010
Edited by N. J. A. Sloane, Apr 21 2010 at the suggestion of R. J. Mathar
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