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Inversion of cycle index sum relations for 2- and 3-connected graphs. (English) Zbl 0728.05026
Algebraic inversion of cycle index sum relations is employed to derive new algorithms for counting unlabeled graphs which are (a) 2-connected, (b) 2-connected and homeomorphically irreducible, and (c) 3-connected. The new algorithms are significantly more efficient than earlier ones, both asymptotically and for modest values of the order. Time- and space- complexity analyses of the algorithms are provided. Tables of computed results are included for the number n of nodes satisfying $$n\leq 26$$ in case (a) and $$n\leq 25$$ in cases (b) and (c). These are totals over all values of the number of q of edges. Reference is made to a technical report available from the authors which includes tables of the values for each q when $$n\leq 16$$ in case (a) and $$n\leq 18$$ in cases (b) and (c).
Reviewer: R.W.Robinson

##### MSC:
 05C30 Enumeration in graph theory 05C40 Connectivity
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