COUNTING ROOTED EULERIAN MAPS ON THE PROJECTIVE PLANE

1IntroductionAsurfaceisacompactclosed2-manifold.Theorielltable(non-orielltable)surfaceofgenuskisthespherewitllkhandles(crosscaPs)denotedbySk(Nk).AmapMollSk(Nk)meansthatitsunderlyinggraphnlaybedrownou(embeddedin)itsuchthatllthpairofedgesintersectataninnerpoilltalldeachfaceishomeomorphictothedisc.Amapisrootedifanedgewithadirectiollalongtheedge,alldasideoftl1eedgeisdistinguisl1ed.Tworootedmapsareconsideredtobethesal11eifthereisanisomorphismpreserviIlgtl1erooting.ArootedEuleriall1llapissuchaon…     

柱面上有根近三角剖分的计数

柱面上的三角剖分是一类与环面上的地图紧密相关的地图．本文提供了一个计算柱面上有根近三角剖分的具有三个变量的精确公式．     

某些曲面上有根近-4-正则欧拉迹的计数

In this article the rooted planar near-4-regular Eulerian trails are enumerated and an explicit formula for such maps is presented. Further, the rooted near-4-regular Eulerian maps on the torus are counted in an exact way.     

COUNTING FAIR NEAR-TRIANGULATIONS ON THE DISC

1IntroductionAp1anarmaPisrootedifauedgeandadirectionalongonesideofitaredistinguished;atriangulationissucharootedplanarmapwhosefaCesareall3-gons;anear-triangulationonthe8phereordiscisarootednonseparableplanarmapsuchthatallofitsfacesexceptpossiblytheroot-faCehavevalencythree.TheenumerationoftriangulationswasfitStintroducedbyTUtteinthebeginningofsixtiesIv9].Infact,thetopicsheworkedweremuchconcentratedonplanartriangularmapsforthesakeofattackingFourColorProblem.Manyelegantresultsrelatedtononsep…     

环面上有根欧拉地图的计数

本文探讨了环面上有限欧拉迹的计算并且提供了一个解析表达式．在此基础上，我们给出了环面上有根欧地图的计算公式．     

The number of rooted essential maps on surfaces

In this paper, general functional equations of rooted essential maps on surfaces （orientable and nonorientable） are deduced and their formal solutions are presented. Further, three explicit for- mulae for counting essential maps on S2,N3 andN4 are given. In the same time, some known results can be derived.     

Counting rooted near-4-regular Eulerian maps on some surfaces

In this article the rooted planar near-4-regular Eulerian trails are enumerated and an explicit formula for such maps is presented. Further, the rooted near-4-regular Eulerian maps on the torus are counted in an exact way.