A324218 - OEIS

%I #27 Mar 17 2020 22:44:27

%S 0,0,1,6,19,49,120,263,571,1149,2259,4218,7679,13437,22952,38013,

%T 61580,97309,150838,229045,342048,502066,726318,1035482,1457677,

%U 2026369,2785873,3788494,5101847,6805192,8998964,11799997,15353938,19829063,25431994,32400113,41021075,51623423

%N Number of connected n-regular loopless multigraphs on six unlabeled nodes.

%C Multigraphs are loopless.

%C Terms computed using 'nauty and Traces' (see the link).

%H Brendan McKay and Adolfo Piperno, <a href="http://pallini.di.uniroma1.it">nauty and Traces</a>

%o (nauty/shell) for ((n=0;n<50;n++)); do geng -c -d1 6 -q | multig -r${n} -u; done

%Y Row n=6 of A328682.

%Y Cf. A324221, A324217.

%K nonn

%O 0,4

%A _Natan Arie Consigli_, Feb 25 2019