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%I #11 Apr 04 2022 06:33:25
%S 1,1,4,28,302,4776,106732,3249352,131290812,6922560160,470586936176,
%T 40833342324864,4482709905772936,617622136930640128,
%U 106013904370382120400,22516967955697072408576,5880701545642715236590608,1877504184190590494772860928
%N Number of labeled connected simple graphs on n vertices without cycles of length 4.
%C From _R. J. Mathar_, Apr 03 2022 (Start)
%C The sequence contains the row sums of the number of labeled connected simple graphs on V vertices with E edges, the triangle with V>=0, E>=0:
%C 1 ;
%C 1 ;
%C 0 1;
%C 0 0 3 1;
%C 0 0 0 16 12;
%C 0 0 0 0 125 162 15;
%C 0 0 0 0 0 1296 2580 900;
%C 0 0 0 0 0 0 16807 47715 35595 6615 ;
%C 0 0 0 0 0 0 0 262144 1006488 1270080 619920 90720;
%C 0 0 0 0 0 0 0 0 4782969 23859108 44893170 39867660 15892065 1995840 ;
%C (End)
%Y LOG transform of A345249.
%Y A077269 counts isomorphism classes.
%Y Cf. A345218.
%K nonn,hard
%O 1,3
%A _Brendan McKay_, Jun 12 2021
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