%I #27 Nov 19 2021 17:41:05
%S 1,1,1,2,4,8,18,47,137,464,1793,8167,43645,275480,2045279,17772647,
%T 179593823,2098423758,28215583324,434936005284,7662164738118
%N Number of n-node connected graphs with no cycles of length less than 5.
%H Keith M. Briggs, <a href="http://keithbriggs.info/cgt.html">Combinatorial Graph Theory</a>
%H CombOS - Combinatorial Object Server, <a href="http://combos.org/nauty">Generate graphs</a>
%F 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
%t A006787 = Cases[Import["https://oeis.org/A006787/b006787.txt", "Table"], {_, _}][[All, 2]];
%t (* EulerInvTransform is defined in A022562 *)
%t EulerInvTransform[A006787] (* _Jean-François Alcover_, May 13 2019, updated Mar 17 2020 *)
%Y Cf. A006787, A140440.
%K nonn,more
%O 1,4
%A _N. J. A. Sloane_, Feb 18 2007
%E Definition corrected by _Max Alekseyev_ and _Brendan McKay_, Jun 17 2008
%E a(20)-a(21) using _Brendan McKay_'s extension to A006787 by _Alois P. Heinz_, Mar 11 2018