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A244534
Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 5.
3
1, 0, 0, 0, 0, 5, 11, 12, 13, 14, 50, 136, 289, 477, 703, 1255, 2611, 5489, 10902, 19712, 35455, 66651, 130014, 254737, 488041, 920461, 1741642, 3338360, 6453073, 12425997, 23780944, 45451155, 87224392, 168253246, 324863578, 625728091, 1202953325, 2314485753
OFFSET
6,6
LINKS
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, 5$2) -b(n-1, 6$2):
seq(a(n), n=6..50);
MATHEMATICA
b[n_, t_, k_] := b[n, t, k] = If[n == 0,
If[MemberQ[{0, k}, t], 1, 0], If[t > n, 0, Sum[b[j-1, k, k]*
b[n-j, Max[0, t-1], k], {j, n}]]];
a[n_] := b[n-1, 5, 5] - b[n-1, 6, 6];
Table[a[n], {n, 6, 50}] (* Jean-François Alcover, Aug 28 2021, after Maple code *)
CROSSREFS
Column k=5 of A244530.
Cf. A244459.
Sequence in context: A289580 A126243 A095805 * A034596 A376594 A166275
KEYWORD
nonn
AUTHOR
Joerg Arndt and Alois P. Heinz, Jun 29 2014
STATUS
approved