Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #16 Oct 26 2019 09:59:12
%S 1,2,4,10,34,148,786,4920,35446,288822,2625844,26349340,289248224,
%T 3447860798,44348374106,612228009210,9028698146956,141655958846642,
%U 2355980548168314,41403643674710280,766627753698325214
%N Related to label-increasing forests with branching bounded by 4.
%C Sequence C_n(2) in Riordan 1978 or 1979.
%H John Riordan, <a href="/A297196/a297196.pdf">Forests of label-increasing trees</a>, annotated scanned copy of 1978 pre-publication version.
%H John Riordan, <a href="https://doi.org/10.1002/jgt.3190030204">Forests of label-increasing trees</a>, J. Graph Theory, 3 (1979), 127-133.
%F E.g.f.: F(x)^2, where F(x) is the e.g.f. for A297200. - _Max Alekseyev_, Jul 12 2019
%Y Cf. A297196, A297197, A297198, A297200, A297202, A297203, A297204.
%K nonn
%O 0,2
%A _N. J. A. Sloane_, Jan 10 2018
%E Edited and more terms added by _Max Alekseyev_, Jul 12 2019