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A318754
Number T(n,k) of rooted trees with n nodes such that k equals the maximal number of subtrees extending from the same node and having the same number of nodes; triangle T(n,k), n>=1, 0<=k<=n-1, read by rows.
13
1, 0, 1, 0, 1, 1, 0, 2, 1, 1, 0, 3, 4, 1, 1, 0, 6, 9, 3, 1, 1, 0, 12, 22, 9, 3, 1, 1, 0, 25, 54, 23, 8, 3, 1, 1, 0, 51, 139, 60, 23, 8, 3, 1, 1, 0, 111, 346, 166, 61, 22, 8, 3, 1, 1, 0, 240, 892, 447, 167, 61, 22, 8, 3, 1, 1, 0, 533, 2290, 1219, 461, 168, 60, 22, 8, 3, 1, 1
OFFSET
1,8
COMMENTS
T(n,k) is defined for n,k >= 0. The triangle contains only the terms with k < n. T(n,k) = 0 for k >= n.
LINKS
FORMULA
T(n,k) = A318753(n,k) - A318753(n,k-1) for k > 0, A(n,0) = A063524(n).
EXAMPLE
Triangle T(n,k) begins:
1;
0, 1;
0, 1, 1;
0, 2, 1, 1;
0, 3, 4, 1, 1;
0, 6, 9, 3, 1, 1;
0, 12, 22, 9, 3, 1, 1;
0, 25, 54, 23, 8, 3, 1, 1;
0, 51, 139, 60, 23, 8, 3, 1, 1;
0, 111, 346, 166, 61, 22, 8, 3, 1, 1;
MAPLE
g:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0, add(
binomial(g(i-1$2, k)+j-1, j)*g(n-i*j, i-1, k), j=0..min(k, n/i))))
end:
T:= (n, k)-> g(n-1$2, k) -`if`(k=0, 0, g(n-1$2, k-1)):
seq(seq(T(n, k), k=0..n-1), n=1..14);
MATHEMATICA
g[n_, i_, k_] := g[n, i, k] = If[n == 0, 1, If[i < 1, 0, Sum[Binomial[g[i - 1, i - 1, k] + j - 1, j]*g[n - i*j, i - 1, k], {j, 0, Min[k, n/i]}]]];
T[n_, k_] := g[n - 1, n - 1, k] - If[k == 0, 0, g[n - 1, n - 1, k - 1]];
Table[T[n, k], {n, 1, 14}, {k, 0, n - 1}] // Flatten (* Jean-François Alcover, May 27 2019, after Alois P. Heinz *)
CROSSREFS
Columns k=0-10 give: A063524, A032305 (for n>1), A318817, A318818, A318819, A318820, A318821, A318822, A318823, A318824, A318825.
Row sums give A000081.
T(2n+2,n+1) give A255705.
Cf. A318753.
Sequence in context: A051509 A124816 A238349 * A318758 A334192 A124790
KEYWORD
nonn,tabl
AUTHOR
Alois P. Heinz, Sep 02 2018
STATUS
approved