• Title/Summary/Keyword: Loopless maps

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ENUMERATION OF LOOPLESS MAPS ON THE PROJECTIVE PLANE

  • Li, Zhaoxiang;Liu, Yanpei
    • Journal of applied mathematics & informatics
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    • v.10 no.1_2
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    • pp.145-155
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    • 2002
  • In this paper we study the rooted loopless maps on the sphere and the projective plane with the valency of root-face and the number of edges as parameters. Explicit expression of enumerating function is obtained for such maps on the sphere and the projective plane. A parametric expression of the generating function is obtained for such maps on the projective plane, from which asymptotic evaluations are derived.

CHROMATIC SUMS OF SINGULAR MAPS ON SOME SURFACES

  • Li, Zhao-Xiang;Liu, Yan-Pei
    • Journal of applied mathematics & informatics
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    • v.15 no.1_2
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    • pp.159-172
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    • 2004
  • A map is singular if each edge is on the same face on a surface (i.e., those have only one face on a surface). Because any map with loop is not colorable, all maps here are assumed to be loopless. In this paper po-vides the explicit expression of chromatic sum functions for rooted singular maps on the projective plane, the torus and the Klein bottle. From the explicit expression of chromatic sum functions of such maps, the explicit expression of enumerating functions of such maps are also derived.