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A126757
Number of n-node connected graphs with no cycles of length less than 5.
4
1, 1, 1, 2, 4, 8, 18, 47, 137, 464, 1793, 8167, 43645, 275480, 2045279, 17772647, 179593823, 2098423758, 28215583324, 434936005284, 7662164738118
OFFSET
1,4
LINKS
CombOS - Combinatorial Object Server, Generate graphs
FORMULA
This is the inverse Euler transform of A006787. - Conjectured by Vladeta Jovovic, Jun 16 2008, proved by Max Alekseyev and Brendan McKay, Jun 17 2008
MATHEMATICA
A006787 = Cases[Import["https://oeis.org/A006787/b006787.txt", "Table"], {_, _}][[All, 2]];
(* EulerInvTransform is defined in A022562 *)
EulerInvTransform[A006787] (* Jean-François Alcover, May 13 2019, updated Mar 17 2020 *)
CROSSREFS
Sequence in context: A252653 A006771 A113989 * A369386 A034766 A099785
KEYWORD
nonn,more
AUTHOR
N. J. A. Sloane, Feb 18 2007
EXTENSIONS
Definition corrected by Max Alekseyev and Brendan McKay, Jun 17 2008
a(20)-a(21) using Brendan McKay's extension to A006787 by Alois P. Heinz, Mar 11 2018
STATUS
approved