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Number of free highly irregular trees with n nodes.
1

%I #15 Oct 31 2023 11:01:10

%S 1,1,0,1,0,0,0,1,1,1,0,0,0,1,1,2,2,5,7,14,19,28,36,51,68,99,128,164,

%T 203,272,203,272,375,576,870,1392,2202,3564,5657,9038,14105,21899

%N Number of free highly irregular trees with n nodes.

%H Alavi, Yousef, Gary Chartrand, Fan RK Chung, Paul Erdős, Ronald L. Graham, and Ortrud R. Oellermann, <a href="http://dx.doi.org/10.1002/jgt.3190110214">Highly irregular graphs</a>, Journal of Graph Theory, 11, no. 2 (1987): 235-249.

%H K. A. McKeon, <a href="/A003609/a003609.pdf">Letter to N. J. A. Sloane</a>, Jul 25 1991. Gives a(n) for n <= 40.

%Y Cf. A259863.

%K nonn,more

%O 1,16

%A _N. J. A. Sloane_, Jul 08 2015