A244462 Number of unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 8.

1, 0, 0, 0, 0, 0, 0, 0, 1, 2, 2, 2, 2, 2, 2, 2, 4, 7, 12, 16, 21, 25, 30, 34, 43, 56, 79, 112, 156, 210, 276, 351, 447, 570, 741, 978, 1314, 1764, 2367, 3137, 4131, 5398, 7058, 9236, 12161, 16077, 21340, 28326, 37573, 49696, 65623, 86526, 114122, 150624

Offset

9,10

Links

Alois P. Heinz, Table of n, a(n) for n = 9..900

Maple

b:= proc(n, i, t, k) option remember; `if`(n=0, `if`(t in [0, k],
      1, 0), `if`(i<1 or t>n, 0, add(binomial(b((i-1)$2, k$2)+j-1, j)*
      b(n-i*j, i-1, max(0, t-j), k), j=0..n/i)))
    end:
a:= n-> b(n-1$2, 8$2) -b(n-1$2, 9$2):
seq(a(n), n=9..70);

Crossrefs

Column k=8 of A244454.

Cf. A244537.

Sequence in context: A280263 A008838 A248783 * A063790 A334510 A211455

Adjacent sequences: A244459 A244460 A244461 * A244463 A244464 A244465

Keyword

nonn

Author

Joerg Arndt and Alois P. Heinz, Jun 29 2014

Status

approved