This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A298118 #15 Jun 04 2019 04:34:53
%S A298118 1,1,1,2,3,6,11,21,40,80,159,322,657,1356,2816,5896,12407,26267,55861,
%T A298118 119331,255878,550665,1188786,2574006,5588177,12162141,26529873,
%U A298118 57993624,127020653,278716336,612617523,1348680531,2973564157,6565313455,14514675376
%N A298118 Number of unlabeled rooted trees with n nodes in which all positive outdegrees are odd.
%H A298118 Alois P. Heinz, <a href="/A298118/b298118.txt">Table of n, a(n) for n = 1..1000</a>
%F A298118 a(n) ~ c * d^n / n^(3/2), where d = 2.30984417428419893876754252289588812511559... and c = 0.5598122522173731208680575003383895445787... - _Vaclav Kotesovec_, Jun 04 2019
%e A298118 The a(6) = 6 trees: (((((o))))), (((ooo))), ((oo(o))), (oo((o))), (o(o)(o)), (ooooo).
%t A298118 orut[n_]:=orut[n]=If[n===1,{{}},Join@@Function[c,Union[Sort/@Tuples[orut/@c]]]/@Select[IntegerPartitions[n-1],OddQ[Length[#]]&]];
%t A298118 Table[Length[orut[n]],{n,15}]
%Y A298118 Cf. A000081, A000598, A003238, A004111, A027193, A032305, A067659, A290689, A291443, A297791, A298120.
%K A298118 nonn
%O A298118 1,4
%A A298118 _Gus Wiseman_, Jan 12 2018
%E A298118 a(24)-a(35) from _Alois P. Heinz_, Jan 12 2018