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A055305
Number of labeled rooted trees with n nodes and 4 leaves.
1
5, 450, 18900, 588000, 15876000, 400075200, 9779616000, 237105792000, 5779453680000, 142845262560000, 3599700616512000, 92818726640640000, 2454539660052480000, 66664716210892800000, 1861170036255129600000
OFFSET
5,1
FORMULA
a(n) = n! * (n-4)^2*(n-3)^2*(n-2)*(n-1)/1152. - Vaclav Kotesovec, 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 *)
PROG
(Magma) [Factorial(n)*(n-4)^2*(n-3)^2*(n-2)*(n-1)/1152 : n in [5..25]]; // Vincenzo Librandi, Jul 25 2014
CROSSREFS
Column 4 of A055302.
Sequence in context: A212042 A177026 A300544 * A300971 A300928 A221626
KEYWORD
nonn
AUTHOR
Christian G. Bower, May 11 2000
STATUS
approved