cp's OEIS Frontend

A128042 Triangle read by columns: number of n-node (unlabeled) connected graphs with girth k, for n >= 3, k >= 3.

%I A128042 #32 Jun 24 2023 13:41:33
%S A128042 1,3,1,15,2,1,93,11,1,1,794,41,5,1,1,10850,220,16,6,1,1,259700,1243,
%T A128042 66,17,5,1,1,11706739,9368,266,69,15,6,1,1,1006609723,89049,1235,239,
%U A128042 58,18,6,1,1,164058686415,1135894,6350,962,202,74,19,7,1,1
%N A128042 Triangle read by columns: number of n-node (unlabeled) connected graphs with girth k, for n >= 3, k >= 3.
%H A128042 Georg Grasegger, <a href="/A128042/b128042.txt">Table of n, a(n) for n = 3..122</a>
%e A128042 Number of n-node (unlabeled) connected graphs with girth k:
%e A128042 .k..|.n=........3........4........5........6........7........8........9........10
%e A128042 ---------------------------------------------------------------------------------
%e A128042 .0..|...........0........0........0........0........0........0........0.........0
%e A128042 .1..|...........0........0........0........0........0........0........0.........0
%e A128042 .2..|...........0........0........0........0........0........0........0.........0
%e A128042 .3..|...........1........3.......15.......93......794....10850...259700..11706739
%e A128042 .4..|...........0........1........2.......11.......41......220.....1243......9368
%e A128042 .5..|...........0........0........1........1........5.......16.......66.......266
%e A128042 .6..|...........0........0........0........1........1........6.......17........69
%e A128042 .7..|...........0........0........0........0........1........1........5........15
%e A128042 .8..|...........0........0........0........0........0........1........1.........6
%e A128042 .9..|...........0........0........0........0........0........0........1.........1
%e A128042 10..|...........0........0........0........0........0........0........0.........1
%e A128042 11..|...........0........0........0........0........0........0........0.........0
%o A128042 (nauty) geng -c $n | countg --ng
%o A128042 # _Martin Fuller_, May 03 2015
%Y A128042 Sequences for k=3..6 are A128240, A128241, A128242, A128243.
%Y A128042 Cf. A128041, A006787, A128236, A128237, A128238, A128239.
%Y A128042 Cf. A325455 (circumference).
%K A128042 nonn,tabl
%O A128042 3,2
%A A128042 _Keith Briggs_, May 05 2007
%E A128042 Corrected and extended by _Martin Fuller_, May 01 2015