A298303 Matula-Goebel numbers of rooted trees with thinning limbs.

1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 14, 15, 16, 18, 20, 21, 22, 24, 25, 26, 27, 28, 30, 31, 32, 33, 35, 36, 39, 40, 42, 44, 45, 46, 48, 49, 50, 52, 54, 55, 56, 58, 60, 62, 63, 64, 65, 66, 69, 70, 72, 75, 76, 77, 78, 80, 81, 84, 86, 87, 88, 90, 91, 92, 93, 94

Offset

1,2

Comments

An unlabeled rooted tree has thinning limbs if its outdegrees are weakly decreasing from root to leaves.

Links

Table of n, a(n) for n=1..67.

Mathematica

MGtree[n_]:=If[n===1, {}, MGtree/@Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
thinQ[t_]:=And@@Cases[t, b_List:>Length[b]>=Max@@Length/@b, {0, Infinity}];
Select[Range[200], thinQ[MGtree[#]]&]

Crossrefs

Cf. A000081, A007097, A061775, A111299, A124343, A124346, A214577, A276625, A290760, A291636, A298126, A298120, A298304, A298305.

Sequence in context: A002180 A207333 A179182 * A333635 A364379 A102799

Adjacent sequences: A298300 A298301 A298302 * A298304 A298305 A298306

Keyword

nonn

Author

Gus Wiseman, Jan 16 2018

Status

approved