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A000418 Number of n-node rooted trees of height 7.
(Formerly M4408 N1862)
2

%I M4408 N1862 #27 Jul 08 2017 01:15:48

%S 0,0,0,0,0,0,0,1,7,34,136,487,1615,5079,15349,45009,128899,362266,

%T 1002681,2740448,7411408,19865445,52840977,139624510,366803313,

%U 958696860,2494322662,6463281890,16686206047,42935345688,110142163940,281763465941

%N Number of n-node rooted trees of height 7.

%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H N. J. A. Sloane, <a href="/A000418/b000418.txt">Table of n, a(n) for n=1..200</a>

%H J. Riordan, <a href="http://dx.doi.org/10.1147/rd.45.0473">Enumeration of trees by height and diameter</a>, IBM J. Res. Dev. 4 (1960), 473-478.

%H <a href="/index/Ro#rooted">Index entries for sequences related to rooted trees</a>

%H <a href="/index/Tra#trees">Index entries for sequences related to trees</a>

%F A034824-A034823. - _Christian G. Bower_

%p For Maple program see link in A000235.

%t b[n_, i_, k_] := b[n, i, k] = If[n == 0, 1, If[i < 1 || k < 1, 0, Sum[ Binomial[b[i - 1, i - 1, k - 1] + j - 1, j]*b[n - i*j, i - 1, k], {j, 0, n/i}]]]; a[n_] := b[n - 1, n - 1, 7] - b[n - 1, n - 1, 6]; Array[a, 40] (* _Jean-François Alcover_, Feb 08 2016, after _Alois P. Heinz_ in A034781 *)

%Y Column h=7 of A034781.

%K nonn

%O 1,9

%A _N. J. A. Sloane_

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Last modified March 28 10:55 EDT 2024. Contains 371241 sequences. (Running on oeis4.)