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A038541
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Number of modules with n elements over ring Z[ sqrt(-5) ].
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0
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1, 1, 2, 2, 1, 2, 2, 3, 5, 1, 0, 4, 0, 2, 2, 5, 0, 5, 0, 2, 4, 0, 2, 6, 2, 0, 10, 4, 2, 2, 0, 7, 0, 0, 2, 10, 0, 0, 0, 3, 2, 4, 2, 0, 5, 2, 2, 10, 5, 2, 0, 0, 0, 10, 0, 6, 0, 2, 0, 4, 2, 0, 10, 11, 0, 0, 2, 0, 4, 2, 0, 15, 0, 0, 4, 0, 0, 0, 0, 5, 20, 2, 2, 8, 0, 2, 4, 0, 2, 5, 0, 4, 0, 2, 0, 14
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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REFERENCES
| P. Samuel, Theorie algebrique des nombres, Hermann Editeurs.
D. Zagier, Zetafunktionen und quadratische Koerper, Springer-Verlag.
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FORMULA
| Define chi(n)=0 if n=2; legendre(-5, n) if n is odd prime; chi(p1)^e1 * ... * chi(pk)^ek if n = p1^e1 * ... * pk^ek; Dirichlet g.f.: sum( a(n) / n^s, n=1..inf) = prod ( Z(ms), m=1..inf)
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CROSSREFS
| Sequence in context: A097266 A112175 A112206 * A070215 A071457 A115034
Adjacent sequences: A038538 A038539 A038540 * A038542 A038543 A038544
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KEYWORD
| nonn,mult
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AUTHOR
| Paolo Dominici (pl.dm(AT)libero.it)
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