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%I #10 May 06 2018 08:42:10
%S 0,0,1,4,14,45,140,424,1269,3760,11080,32517,95190,278154,811887,
%T 2367973,6903453,20120905,58639016,170894228,498084608,1451899005,
%U 4232957241,12343454790,36001675800,105028397290,306472665459,894497511566
%N Number of trees on n vertices rooted at an oriented non-edge.
%F A000106(n) + a(n) = A000243(n).
%e a(4)=4 is based on the same examples as in A304067, but the oriented edge that spans a leaf with the node at distance 2 in the linear graph may have 2 orientations, so a(4) is one larger than A304067(4).
%Y Cf. A000055 (not rooted), A000106 (rooted at oriented edge)
%K nonn
%O 1,4
%A _Brendan McKay_, May 05 2018
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