OFFSET
1,5
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..200
FORMULA
EXAMPLE
The a(1) = 1 through a(7) = 20 trees:
o . (oo) (ooo) (oooo) (ooooo) (oooooo)
((ooo)) ((oooo)) ((ooooo))
(o(oo)) (o(ooo)) (o(oooo))
(oo(o)) (oo(oo)) (oo(ooo))
(ooo(o)) (ooo(oo))
(oooo(o))
(((oooo)))
((o)(ooo))
((o(ooo)))
((oo)(oo))
((oo(oo)))
((ooo(o)))
(o((ooo)))
(o(o)(oo))
(o(o(oo)))
(o(oo(o)))
(oo((oo)))
(oo(o)(o))
(oo(o(o)))
(ooo((o)))
MATHEMATICA
art[n_]:=If[n==1, {{}}, Join@@Table[Select[Tuples[art/@c], OrderedQ], {c, Join@@Permutations/@IntegerPartitions[n-1]}]];
Table[Length[Select[art[n], Count[#, {}, {0, Infinity}]>Count[#, _[__], {0, Infinity}]&]], {n, 0, 10}]
PROG
(PARI) \\ See A358584 for R(n).
seq(n) = {my(A=R(n)); vector(n, n, my(u=Vecrev(A[n]/y)); vecsum(u[n\2+1..#u]))} \\ Andrew Howroyd, Dec 31 2022
CROSSREFS
The non-strict version is A358583.
KEYWORD
nonn
AUTHOR
Gus Wiseman, Nov 23 2022
EXTENSIONS
Terms a(19) and beyond from Andrew Howroyd, Dec 31 2022
STATUS
approved