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A290361 Number of 7-leaf rooted trees with n levels. 2

%I

%S 0,1,15,111,518,1789,5026,12166,26328,52221,96613,168861,281502,

%T 450905,697984,1048972,1536256,2199273,3085467,4251307,5763366,

%U 7699461,10149854,13218514,17024440,21703045,27407601,34310745,42606046,52509633,64261884,78129176

%N Number of 7-leaf rooted trees with n levels.

%H Alois P. Heinz, <a href="/A290361/b290361.txt">Table of n, a(n) for n = 0..1000</a>

%H B. A. Huberman and T. Hogg, <a href="https://doi.org/10.1016/0167-2789(86)90308-1">Complexity and adaptation</a>, Evolution, games and learning (Los Alamos, N.M., 1985). Phys. D 22 (1986), no. 1-3, 376-384.

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

%H <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (7,-21,35,-35,21,-7,1).

%F G.f.: -(4*x^4+21*x^3+27*x^2+8*x+1)*x / (x-1)^7.

%F a(n) = (61*n^6+69*n^5+145*n^4+195*n^3+154*n^2+96*n)/6!.

%p a:= n-> (((((61*n+69)*n+145)*n+195)*n+154)*n+96)*n/6!:

%p seq(a(n), n=0..40);

%Y Row n=7 of A290353.

%K nonn,easy

%O 0,3

%A _Alois P. Heinz_, Jul 28 2017

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Last modified May 19 04:06 EDT 2019. Contains 323377 sequences. (Running on oeis4.)