[go: up one dir, main page]

login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Number of labeled rooted trees with n nodes and 8 leaves.
1

%I #14 Sep 08 2022 08:45:01

%S 9,22950,9236700,1731510000,213034536000,20154167953920,

%T 1599866940672000,112412172128256000,7240640845838400000,

%U 437993205197708160000,25315591135036262860800

%N Number of labeled rooted trees with n nodes and 8 leaves.

%H Vincenzo Librandi, <a href="/A055309/b055309.txt">Table of n, a(n) for n = 9..200</a>

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

%F a(n) = n! * (n-8)^2*(n-7)^2*(n-6)*(n-5)*(n-4)*(n-3)*(n-2)*(n-1)*(9*n^4 - 234*n^3 + 2211*n^2 - 8938*n + 12960)/234101145600. - _Vaclav Kotesovec_, Jul 25 2014

%t Table[n! * (n-8)^2*(n-7)^2*(n-6)*(n-5)*(n-4)*(n-3)*(n-2)*(n-1)*(9*n^4 - 234*n^3 + 2211*n^2 - 8938*n + 12960)/234101145600,{n,9,20}] (* _Vaclav Kotesovec_, Jul 25 2014 *)

%o (Magma) [Factorial(n)*(n-8)^2*(n-7)^2*(n-6)*(n-5)*(n-4)*(n-3)*(n-2)*(n-1)*(9*n^4 - 234*n^3 + 2211*n^2 - 8938*n + 12960)/234101145600 : n in [9..25]]; // _Vincenzo Librandi_, Jul 25 2014

%Y Column 8 of A055302.

%K nonn

%O 9,1

%A _Christian G. Bower_, May 11 2000