A318902 Number of n-node rooted trees in which six equals the maximal number of nodes in paths starting at a leaf and ending at the first branching node or at the root.

1, 1, 3, 8, 22, 60, 166, 461, 1291, 3629, 10246, 29020, 82448, 234818, 670288, 1917054, 5492422, 15760308, 45286760, 130293687, 375293797, 1082109082, 3123088057, 9021467714, 26080762653, 75454838291, 218451043430, 632849337956, 1834453919208, 5320549626803

Offset

6,3

Links

Alois P. Heinz, Table of n, a(n) for n = 6..2138

Maple

g:= proc(n, k) option remember; `if`(n=0, 1, add(add(d*(g(d-1, k)-
      `if`(d=k, 1, 0)), d=numtheory[divisors](j))*g(n-j, k), j=1..n)/n)
    end:
a:= n-> (k-> g(n-1, k) -g(n-1, k-1))(6):
seq(a(n), n=6..36);

Crossrefs

Column k=6 of A255704.

Sequence in context: A024581 A028859 A155020 * A318903 A318904 A318905

Adjacent sequences: A318899 A318900 A318901 * A318903 A318904 A318905

Keyword

nonn

Author

Alois P. Heinz, Sep 05 2018

Status

approved