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A141316
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Conjecturally, number of generators of degree n of the Hopf algebra of parking functions, regarded as a dendriform trialgebra.
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0
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1, 0, 5, 50, 634, 9475, 163843, 3226213, 71430404, 1759835599, 47821543220, 1422411027534, 46002758077823, 1608256429511163, 60463005173005523, 2433267830904336072, 104394054462487756061, 4757234883237958801214
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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REFERENCES
| J.-C. Novelli and J.-Y. Thibon, Hopf algebras and dendriform structures arising from parking functions, Fundamenta Math. 193 (2007), 189-241.
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LINKS
| J.-C. Novelli and J.-Y. Thibon, Free quasi-symmetric functions and descent algebras for wreath products and noncommutative multi-symmetric functions
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FORMULA
| Generating function: sum a(n)*t^n = (f(t)-1)/(2f(t)^2-f(t)) where f(t) = 1 + sum ( (n+1)^(n-1)*t^n, n >=1)
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MAPLE
| f:=proc(N); 1+sum((n+1)^(n-1)*t^n, n=1..N); end; g:=proc(N); taylor( (f(N)-1)/(2*f(N)^2-f(N)), t, N+1); end; a:=proc(n); coeff(g(n), t, n); end;
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CROSSREFS
| Cf. A122705, A122708.
Sequence in context: A156058 A047736 A185272 * A093146 A049393 A047054
Adjacent sequences: A141313 A141314 A141315 * A141317 A141318 A141319
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KEYWORD
| nonn
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AUTHOR
| Jean-Yves Thibon (jyt(AT)univ-mlv.fr), Jun 26 2008
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