[go: up one dir, main page]
login
The OEIS is supported by the many generous donors to the OEIS Foundation.
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A085617
Number of nonisomorphic 2-graphs with 2n nodes with first cohomology invariant nonzero, second cohomology invariant 0.
1
0, 0, 2, 17, 392
(list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
LINKS
Table of n, a(n) for n=1..5.
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.
CROSSREFS
Cf. A006627, A002854.
Sequence in context: A319591 A198405 A202972 * A152557 A015202 A308864
Adjacent sequences: A085614 A085615 A085616 * A085618 A085619 A085620
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jul 11 2003
STATUS
approved

Lookup Welcome Wiki Register Music Plot 2 Demos Index WebCam Contribute Format Style Sheet Transforms Superseeker Recents
The OEIS Community
Maintained by The OEIS Foundation Inc.
Last modified November 7 19:25 EST 2024. Contains 377536 sequences.
License Agreements, Terms of Use, Privacy Policy