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A007836
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Springer numbers associated with symplectic group.
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3
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1, 1, 1, 5, 23, 151, 1141, 10205, 103823, 1190191, 15151981, 212222405, 3242472023, 53670028231, 956685677221, 18271360434605, 372221031054623, 8056751598834271, 184647141575344861, 4466900836910758805
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,4
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COMMENTS
| Comments from F. Chapoton (fchapoton2(AT)gmail.com), Oct 30 2009: To compute this sequence, I used something similar to the Boustrophedon definition of the Euler numbers, but with two triangles instead of one. This is described (page 94) in Arnold's article in "Lecons de mathematiques d'aujourd'hui, volume 1" Editions Cassini. This is very similar to A001586, except that the initial conditions ( (0,1) at top of the two triangles ) are exchanged.
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REFERENCES
| V. I. Arnold, The calculus of snakes and the combinatorics of Bernoulli, Euler and Springer numbers of Coxeter groups, Uspekhi Mat. Nauk., 47 (#1, 1992), 3-45 = Russian Math. Surveys, Vol. 47 (1992), 1-51.
V. I. Arnold, Nombres d'Euler, de Bernoulli et de Springer pour les groupes de Coxeter et les espaces de morsification : le calcul des serpents, in "Lecons de mathematiques d'aujourd'hui, volume 1", Editions Cassini.
M. Josuat-Verges, J.-C. Novelli and J.-Y. Thibon, The algebraic combinatorics of snakes, Arxiv preprint arXiv:1110.5272, 2011
A. Vieru, Agoh's conjecture: its proof, its generalizations, its analogues, Arxiv preprint arXiv:1107.2938, 2011.
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LINKS
| F. Chapoton, Sage program
Michael E. Hoffman, DERIVATIVE POLYNOMIALS, EULER POLYNOMIALS, AND ASSOCIATED INTEGER SEQUENCES
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FORMULA
| a(m) = P_n(1) - Q_n(1) (see A155100 and A104035), defining Q_{-1} = 0. Cf. A156142.
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CROSSREFS
| Cf. A001586, A155100, A104035, A156142.
Sequence in context: A047049 A020034 A128884 * A157306 A054749 A107204
Adjacent sequences: A007833 A007834 A007835 * A007837 A007838 A007839
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KEYWORD
| nonn,nice
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
| More terms from F. Chapoton (fchapoton2(AT)gmail.com), Oct 30 2009
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