A128241 - OEIS

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A128241

Number of n-node (unlabeled) connected graphs with girth 4.

%I #10 Aug 15 2019 16:59:01

%S 0,1,2,11,41,220,1243,9368,89049,1135894,19381407,445505570,

%T 13741579905,566739127723,31124921885829

%N Number of n-node (unlabeled) connected graphs with girth 4.

%F a(n) = A024607(n) - A126757(n). - _Martin Fuller_, May 01 2015

%Y Cf. A024607, A126757.

%Y Cf. A128041, A128042, A128236-A128243.

%K nonn,more

%O 3,3

%A _Keith Briggs_, May 05 2007

%E Corrected and extended by _Martin Fuller_, May 01 2015