A055305 Number of labeled rooted trees with n nodes and 4 leaves.

5, 450, 18900, 588000, 15876000, 400075200, 9779616000, 237105792000, 5779453680000, 142845262560000, 3599700616512000, 92818726640640000, 2454539660052480000, 66664716210892800000, 1861170036255129600000

Offset: 5

Author

Christian G. Bower, May 11 2000

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 5..200
• Index entries for sequences related to rooted trees

Crossrefs

Column 4 of A055302.

Programs

Magma

[Factorial(n)*(n-4)^2*(n-3)^2*(n-2)*(n-1)/1152 : n in [5..25]]; // Vincenzo Librandi, Jul 25 2014

Mathematica

Table[n! * (n-4)^2*(n-3)^2*(n-2)*(n-1)/1152,{n,5,20}] (* Vaclav Kotesovec, Jul 25 2014 *)

Formula

a(n) = n! * (n-4)^2*(n-3)^2*(n-2)*(n-1)/1152. - Vaclav Kotesovec, Jul 25 2014