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A046001
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Maximal number of ordinary double points on an n-th degree algebraic surface in complex projective 3-space.
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0
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OFFSET
| 1,3
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REFERENCES
| S. Endrass, Flaechen mit vielen Doppelpunkten. DMV-Mitteilungen 4 (April 1995), 17-20.
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LINKS
| S. Endrass, Surfaces with many ordinary nodes
Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.
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EXAMPLE
| For n = 3 there is a unique surface of degree 3 with 4 double points, Cayley's cubic: 4(w^3+x^3+y^3+z^3) = (w+x+y+z)^3.
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CROSSREFS
| Sequence in context: A173019 A031003 A036345 * A031050 A119677 A126032
Adjacent sequences: A045998 A045999 A046000 * A046002 A046003 A046004
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KEYWORD
| nonn,nice,hard
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AUTHOR
| Eric Weisstein (eric(AT)weisstein.com)
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EXTENSIONS
| For n >= 7 lower bounds are 93,168,216,345; upper bounds are 104, 174, 246, 360
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