id:A067309 - OEIS Search Results

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Number of symmetric unlabeled digraphs (unlabeled digraphs with nontrivial automorphism group).

+0
1

0, 0, 2, 9, 82, 1607, 95647 (list; graph; listen)

	OFFSET	`0,3`
	FORMULA	`a(n)=A000273(n)-A051504(4)`
	EXAMPLE	`For n=4 nodes from the 218 (=A000273(4)) unlabeled nonisomorphic digraphs 136(=A051504(4)) are asymmetric, so 218-136=82 are somehow symmetric.`
	CROSSREFS	`Cf. A000273, A051504.` `Sequence in context: A117581 A123570 A006040 this_sequence A087798 A113146 A069234` `Adjacent sequences: A067306 A067307 A067308 this_sequence A067310 A067311 A067312`
	KEYWORD	`nonn`
	AUTHOR	`Labos E. (labos(AT)ana.sote.hu), Jan 11 2002`

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Last modified November 30 13:13 EST 2009. Contains 167758 sequences.