A055316 Number of labeled trees with n nodes and 4 leaves.

5, 210, 5250, 109200, 2116800, 40219200, 768398400, 14968800000, 299675376000, 6193291104000, 132456516192000, 2935293064704000, 67432408243200000, 1605928737853440000, 39636028549877760000

Offset

5,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 5..200

Index entries for sequences related to trees

Formula

(n!/4!)*stirling2(n-2, n-4). - Vladeta Jovovic, Jan 28 2004

a(n) = n! * (n-4)*(n-3)*(n-2)*(3*n-11)/576. - Vaclav Kotesovec, Jul 25 2014

Mathematica

Table[n! * (n-4)*(n-3)*(n-2)*(3*n-11)/576, {n, 5, 20}] (* Vaclav Kotesovec, Jul 25 2014 *)

Prog

(Magma) [Factorial(n)*(n-4)*(n-3)*(n-2)*(3*n-11)/576: n in [5..25]]; // Vincenzo Librandi, Jul 25 2014

Crossrefs

Column 4 of A055314.

Sequence in context: A144139 A020541 A006413 * A203470 A165208 A293652

Adjacent sequences: A055313 A055314 A055315 * A055317 A055318 A055319

Keyword

nonn

Author

Christian G. Bower, May 11 2000

Status

approved