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A071547
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Determinant of the n X n matrix whose element (i,j) equals f(|i-j|) where f(n) is the sum of middle divisors (A071090).
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0
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0, -1, 2, 0, -2, 3, 8, -259, -9006, 37575, 1988916, 41615129, -444915500, 4752358604, -50506657344, 532544416084, -4450492081868, -10234691885873, 241215169689690, 21696729746925312, 123619114295636184, 174381272189413488, -43909101832286346168, -439142701170244441024
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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MATHEMATICA
| f[n_] := If[n > 0, Plus @@ Select[Divisors[n], Sqrt[n/2] <= # < Sqrt[n*2] &], 0]; Table[ Det[ Table[ f[ Abs[i - j]], {i, 1, n}, {j, 1, n}]], {n, 1, 25}]
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CROSSREFS
| Cf. A071090.
Sequence in context: A059235 A178516 A072514 * A089839 A206823 A151668
Adjacent sequences: A071544 A071545 A071546 * A071548 A071549 A071550
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KEYWORD
| sign
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AUTHOR
| Robert G. Wilson v (rgwv(AT)rgwv.com), May 30 2002
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