A055320 Number of labeled trees with n nodes and 8 leaves.

9, 11430, 2994750, 405167400, 38104981200, 2861947408320, 185364917337600, 10851787634688000, 592181546628672000, 30766166997261696000, 1544883657843618892800, 75806672148355180032000

Offset: 9

Author

Christian G. Bower, May 11 2000

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 9..200
• Index entries for sequences related to trees

Crossrefs

Column 8 of A055314.

Programs

Magma

[Factorial(n)*(n-8)*(n-7)*(n-6)*(n-5)*(n-4)*(n-3)*(n-2)*(63*n^5 - 2205*n^4 + 30555*n^3 - 209251*n^2 + 707014*n - 940896)/117050572800: n in [9..25]]; // Vincenzo Librandi, Jul 25 2014

Mathematica

Table[n! * (n-8)*(n-7)*(n-6)*(n-5)*(n-4)*(n-3)*(n-2)*(63*n^5 - 2205*n^4 + 30555*n^3 - 209251*n^2 + 707014*n - 940896)/117050572800,{n,9,20}] (* Vaclav Kotesovec, Jul 25 2014 *)

Formula

(n!/8!)*Stirling2(n-2, n-8). - Vladeta Jovovic, Jan 28 2004

a(n) = n! * (n-8)*(n-7)*(n-6)*(n-5)*(n-4)*(n-3)*(n-2)*(63*n^5 - 2205*n^4 + 30555*n^3 - 209251*n^2 + 707014*n - 940896)/117050572800. - Vaclav Kotesovec, Jul 25 2014