A345249 - OEIS

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A345249

Number of labeled simple graphs on n vertices without cycles of length 4.

4

1, 2, 8, 54, 548, 7984, 163440, 4599908, 174204728, 8721120744, 568964631296, 47787888342520, 5112015062311008, 689824902243337856, 116423739687724785152, 24387469030487505651984, 6296486009090647137387200, 1991072810881504185092485408

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..18.

Index entries for sequences of squarefree graphs

CROSSREFS

EXP transform of A345248. Row sums of A352472.

A006786 counts isomorphism classes.

Cf. A213434, A352258 (loops allowed).

Sequence in context: A005155 A133316 A234301 * A005440 A183282 A139016

Adjacent sequences: A345246 A345247 A345248 * A345250 A345251 A345252

KEYWORD

nonn,hard

AUTHOR

Brendan McKay, Jun 12 2021

STATUS

approved