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Search: id:A004304
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| A004304 |
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Number of planar tree-rooted maps with n edges.
(Formerly M0364)
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+0
2
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| 1, 2, 2, 6, 28, 160, 1036, 7294, 54548, 426960, 3463304, 28910816, 247104976, 2154192248, 19097610480, 171769942086, 1564484503044, 14407366963440, 133978878618904, 1256799271555872, 11881860129979440
(list; graph; listen)
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OFFSET
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0,2
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REFERENCES
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Walsh, T. R. S.; Lehman, A. B.; Counting rooted maps by genus. III: Nonseparable maps. J. Combinatorial Theory Ser. B 18 (1975), 222-259.
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MAPLE
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A004304 := proc(n) local N, x, ode ; Order := n+1 ; ode := x^2*diff(N(x), x, x)*(N(x)^3-16*x*N(x)) ; ode := ode + (x*diff(N(x), x))^3*(16-6*N(x)) ; ode := ode + (x*diff(N(x), x))^2*(12*N(x)^2-16*x-24*N(x)) ; ode := ode + x*diff(N(x), x)*(-8*N(x)^3+24*x*N(x)+12*N(x)^2) ; ode := ode + 2*N(x)^2*(N(x)^2-N(x)-6*x) ; dsolve({ode=0, N(0)=1, D(N)(0)=2}, N(x), type=series) ; convert(%, polynom) ; rhs(%) ; RETURN( coeftayl(%, x=0, n)) ; end; for n from 0 to 20 do printf("%d, ", A004304(n)) ; od ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 18 2006
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CROSSREFS
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Cf. A000264.
Adjacent sequences: A004301 A004302 A004303 this_sequence A004305 A004306 A004307
Sequence in context: A135407 A076726 A032272 this_sequence A108800 A058250 A067644
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KEYWORD
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nonn
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AUTHOR
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njas
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EXTENSIONS
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More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 18 2006
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