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A085618 Number of self-complementary 2-graphs with n nodes. 2
1, 1, 4, 0, 19, 10 (list; graph; refs; listen; history; text; internal format)
OFFSET
4,3
COMMENTS
Sozański (1980, p. 141) says: "Note that formula (20) also gives the number of isomorphism classes of self-complementary p-point two-graphs." Formula (20) apparently refers to sequence A263626 (according to the references there). Is this sequence the same as A263626? (This would mean a(n) = 0 for 3 == n mod 4.) - Petros Hadjicostas, Feb 27 2021
LINKS
F. C. Bussemaker, R. A. Mathon and J. J. Seidel, Tables of two-graphs, T.H.-Report 79-WSK-05, Technological University Eindhoven, Dept. Mathematics, 1979; also pp. 71-112 of "Combinatorics and Graph Theory (Calcutta, 1980)", Lect. Notes Math. 885, 1981.
F. C. Bussemaker, R. A. Mathon and J. J. Seidel, Tables of two-graphs, T.H.-Report 79-WSK-05, Technological University Eindhoven, Dept. Mathematics, 1979; also pp. 71-112 of "Combinatorics and Graph Theory (Calcutta, 1980)", Lect. Notes Math. 885, 1981.
Tadeusz Sozański, Enumeration of weak isomorphism classes of signed graphs, J. Graph Theory 4 (1980), no. 2, 127-144.
CROSSREFS
Sequence in context: A184946 A351615 A362058 * A263626 A282579 A283012
KEYWORD
nonn,more
AUTHOR
N. J. A. Sloane, Jul 11 2003
STATUS
approved

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Last modified March 28 04:13 EDT 2024. Contains 371235 sequences. (Running on oeis4.)