A244538 Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 9.

1, 0, 0, 0, 0, 0, 0, 0, 0, 9, 19, 20, 21, 22, 23, 24, 25, 26, 144, 406, 841, 1335, 1891, 2512, 3201, 3961, 4795, 7491, 14467, 28861, 54626, 94160, 150101, 225337, 323016, 446556, 629454, 949486, 1545877, 2639756, 4558225, 7716325, 12629776, 19928727, 30372551

Offset

10,10

Links

Alois P. Heinz, Table of n, a(n) for n = 10..1000

Maple

b:= proc(n, t, k) option remember; `if`(n=0,
      `if`(t in [0, k], 1, 0), `if`(t>n, 0, add(b(j-1, k$2)*
       b(n-j, max(0, t-1), k), j=1..n)))
    end:
a:= n-> b(n-1, 9$2) -b(n-1, 10$2):
seq(a(n), n=10..60);

Crossrefs

Column k=9 of A244530.

Cf. A244463.

Sequence in context: A107780 A288392 A157140 * A242332 A357773 A075981

Adjacent sequences: A244535 A244536 A244537 * A244539 A244540 A244541

Keyword

nonn

Author

Joerg Arndt and Alois P. Heinz, Jun 29 2014

Status

approved