A231869 - OEIS

%I #14 Nov 20 2022 03:22:45

%S 1,12,122,123,1222,1223,1232,1233,1234,12222,12223,12232,12233,12234,

%T 12322,12323,12332,12333,12334,12342,12343,12344,12345

%N Elements of the planar rooted trees sub-operad PRT of TN generated by 01.

%C Since nonzero terms in the OEIS may not begin with 0, 1 has been added to all the digits.

%H S. Giraudo, <a href="http://arxiv.org/abs/1306.6938">Combinatorial operads from monoids</a>, arXiv preprint arXiv:1306.6938 [math.CO], 2013-2015.

%K nonn,more

%O 1,2

%A _N. J. A. Sloane_, Nov 14 2013