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Search: id:A007993
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| A007993 |
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Poincare series of Lie algebra associated with a certain braid group. |
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+0
1
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| 3, 12, 40, 102, 219, 419, 738, 1221, 1923, 2910, 4260, 6064, 8427, 11469, 15326, 20151, 26115, 33408, 42240, 52842, 65467, 80391, 97914, 118361, 142083, 169458, 200892, 236820, 277707, 324049, 376374, 435243, 501251, 575028, 657240
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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The series in the Humphries paper has zeros interleaved.
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REFERENCES
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S. P. Humphries, Braid groups, infinite Lie algebras of Cartan type and rings of invariants, Topology and its Applications, 95 (3) (1999) pp. 173-205.
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LINKS
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S. P. Humphries, Home page
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FORMULA
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The polynomial 3 + 9(n-1) + 19(n-1)(n-2)/2 + 15(n-1)(n-2)(n-3)/6 + 6(n-1)(n-2)(n-3)(n-4)/24 + (n-1)(n-2)(n-3)(n-4)(n-5)/120 fits the 15 listed terms - John W. Layman (layman(AT)math.vt.edu (May 12, 1999))
(1/120) [n^5 + 10n^4 + 35n^3 - 10n^2 - 396n + 720 ]. - Ralf Stephan (ralf(AT)ark.in-berlin.de), Jun 11 2005
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CROSSREFS
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Sequence in context: A062311 A034956 A032093 this_sequence A052482 A080929 A061136
Adjacent sequences: A007990 A007991 A007992 this_sequence A007994 A007995 A007996
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KEYWORD
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nonn
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AUTHOR
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Stephen P Humphries (steve(AT)math.byu.edu)
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EXTENSIONS
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More terms from Ralf Stephan (ralf(AT)ark.in-berlin.de), Jun 11 2005
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