A244535 Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 6.

1, 0, 0, 0, 0, 0, 6, 13, 14, 15, 16, 17, 69, 190, 400, 651, 946, 1288, 2186, 4425, 9126, 17811, 31654, 51997, 85841, 149916, 276056, 518089, 960466, 1718395, 3006963, 5269873, 9392821, 17032418, 31098198, 56432687, 101350402, 180978701, 323731177, 582832779

Offset

7,7

Links

Alois P. Heinz, Table of n, a(n) for n = 7..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, 6$2) -b(n-1, 7$2):
seq(a(n), n=7..50);

Crossrefs

Column k=6 of A244530.

Cf. A244460.

Sequence in context: A090324 A106623 A115010 * A066826 A031113 A112610

Adjacent sequences: A244532 A244533 A244534 * A244536 A244537 A244538

Keyword

nonn

Author

Joerg Arndt and Alois P. Heinz, Jun 29 2014

Status

approved