A244463 Number of 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, 1, 2, 2, 2, 2, 2, 2, 2, 2, 4, 7, 12, 16, 21, 25, 30, 34, 39, 47, 61, 83, 117, 160, 215, 280, 356, 442, 549, 682, 864, 1112, 1458, 1919, 2533, 3313, 4298, 5521, 7057, 8995, 11497, 14751, 19042, 24687, 32102, 41731, 54172, 70112, 90535

Offset

10,11

Links

Alois P. Heinz, Table of n, a(n) for n = 10..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, 9$2) -b(n-1$2, 10$2):
seq(a(n), n=10..75);

Crossrefs

Column k=9 of A244454.

Cf. A244538.

Sequence in context: A248774 A104274 A008857 * A307590 A307987 A047935

Adjacent sequences: A244460 A244461 A244462 * A244464 A244465 A244466

Keyword

nonn

Author

Joerg Arndt and Alois P. Heinz, Jun 29 2014

Status

approved