A345249 Number of labeled simple graphs on n vertices without cycles of length 4.

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

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