A055318 Number of labeled trees with n nodes and 6 leaves.

7, 1736, 151704, 8573040, 385363440, 15186346560, 553400527680, 19255141825920, 652932709228800, 21874544352460800, 730877395478630400, 24516805259429683200, 829582077548941516800, 28413517892377153536000

Offset: 7

Author

Christian G. Bower, May 11 2000

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 7..200
• Index entries for sequences related to trees

Crossrefs

Column 6 of A055314.

Programs

Magma

[Factorial(n)*(n-6)*(n-5)*(n-4)*(n-3)*(n-2)*(15*n^3 - 240*n^2 + 1265*n - 2192)/4147200: n in [7..25]]; // Vincenzo Librandi, Jul 25 2014

Mathematica

Table[n! * (n-6)*(n-5)*(n-4)*(n-3)*(n-2)*(15*n^3 - 240*n^2 + 1265*n - 2192)/4147200,{n,7,20}] (* Vaclav Kotesovec, Jul 25 2014 *)

Formula

(n!/6!)*Stirling2(n-2, n-6). - Vladeta Jovovic, Jan 28 2004

a(n) = n! * (n-6)*(n-5)*(n-4)*(n-3)*(n-2)*(15*n^3 - 240*n^2 + 1265*n - 2192)/4147200. - Vaclav Kotesovec, Jul 25 2014