A055308 - OEIS

%I #16 Sep 08 2022 08:45:01

%S 8,9144,2178000,270111600,23449219200,1635398519040,98861289246720,

%T 5425893817344000,278673669001728000,13673851998782976000,

%U 650477329618365849600,30322668859342072012800

%N Number of labeled rooted trees with n nodes and 7 leaves.

%H Vincenzo Librandi, <a href="/A055308/b055308.txt">Table of n, a(n) for n = 8..200</a>

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

%F a(n) = n! * (n-7)*(n-6)*(n-5)*(n-4)*(n-3)*(n-2)*(n-1)*(63*n^5 - 1890*n^4 + 22365*n^3 - 130186*n^2 + 371672*n - 414720)/14631321600. - _Vaclav Kotesovec_, Jul 25 2014

%t Table[n! * (n-7)*(n-6)*(n-5)*(n-4)*(n-3)*(n-2)*(n-1)*(63*n^5 - 1890*n^4 + 22365*n^3 - 130186*n^2 + 371672*n - 414720)/14631321600,{n,8,20}] (* _Vaclav Kotesovec_, Jul 25 2014 *)

%o (Magma) [Factorial(n)*(n-7)*(n-6)*(n-5)*(n-4)*(n-3)*(n-2)*(n-1)*(63*n^5- 1890*n^4+22365*n^3-130186*n^2+371672*n-414720)/14631321600: n in [8..25]]; // _Vincenzo Librandi_, Jul 25 2014

%Y Column 7 of A055302.

%K nonn

%O 8,1

%A _Christian G. Bower_, May 11 2000