Some Easily Derivable Integer Sequences

نویسنده

  • Valery A. Liskovets
چکیده

We propose and discuss several simple ways of obtaining new enumerative sequences from existing ones. For instance, the number of graphs considered up to the action of an involutory transformation is expressible as the semi-sum of the total number of such graphs and the number of graphs invariant under the involution. Another, less familiar idea concerns evenand odd-edged graphs: the difference between their numbers often proves to be a very simple quantity (such as n!). More than 30 new sequences will be constructed by these methods. Acknowledgement. This research was supported by INTAS (Grant INTAS-BELARUS 97-0093). Mathematics Subject Classification (1991): 05C30, 05A19

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تاریخ انتشار 2000