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A099881 Number of pairs of n-node simple graphs that are isospectral (excluding triples, etc.). 2
0, 0, 0, 0, 1, 5, 52, 771, 21025 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

Table of n, a(n) for n=1..9.

Eric Weisstein's World of Mathematics, Isospectral Graphs

CROSSREFS

Cf. A099882, A099883.

Sequence in context: A193809 A134111 A071583 * A280063 A196531 A108459

Adjacent sequences:  A099878 A099879 A099880 * A099882 A099883 A099884

KEYWORD

nonn,more

AUTHOR

Eric W. Weisstein, Oct 28 2004

STATUS

approved

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Last modified May 6 09:45 EDT 2021. Contains 343580 sequences. (Running on oeis4.)