A055319 Number of labeled trees with n nodes and 7 leaves.

8, 4536, 695520, 61538400, 4041576000, 221759778240, 10852244282880, 492871809830400, 21317707547136000, 893639962575360000, 36758908512752025600, 1496966633049426739200, 60752381255663505408000, 2469167757848774062080000, 100876656745052194406400000

Offset: 8

Author

Christian G. Bower, May 11 2000

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 8..200
• Index entries for sequences related to trees

Crossrefs

Column 7 of A055314.

Programs

Magma

[Factorial(n)*(n-7)^2*(n-6)^2*(n-5)*(n-4)*(n-3)*(n-2)*(3*n^2 - 35*n + 96)/58060800: n in [8..25]]; // Vincenzo Librandi, Jul 25 2014

Mathematica

Table[n! * (n-7)^2*(n-6)^2*(n-5)*(n-4)*(n-3)*(n-2)*(3*n^2 - 35*n + 96)/58060800,{n,8,20}] (* Vaclav Kotesovec, Jul 25 2014 *)

Formula

a(n) = (n!/7!)*Stirling2(n-2, n-7). - Vladeta Jovovic, Jan 28 2004

a(n) = n! * (n-7)^2*(n-6)^2*(n-5)*(n-4)*(n-3)*(n-2)*(3*n^2 - 35*n + 96)/58060800. - Vaclav Kotesovec, Jul 25 2014