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A055321
Number of labeled trees with n nodes and 9 leaves.
1
10, 28050, 12315600, 2501070000, 331387056000, 33590279923200, 2844207894528000, 212334102908928000, 14481281691676800000, 924652322084050560000, 56256869188969473024000, 3303981073122303974400000, 189156797595688810567680000, 10636600593905858347776000000
OFFSET
10,1
FORMULA
a(n) = (n!/9!)*Stirling2(n-2, n-9). - Vladeta Jovovic, Jan 28 2004
a(n) = n! * (n-9)^2*(n-8)^2*(n-7)*(n-6)*(n-5)*(n-4)*(n-3)*(n-2)*(9*n^4 - 270*n^3 + 2967*n^2 - 14098*n + 24352)/2106910310400. - Vaclav Kotesovec, Jul 25 2014
MAPLE
a:= n-> (n!/9!)*Stirling2(n-2, n-9):
seq(a(n), n=10..25); # Alois P. Heinz, Mar 06 2012
MATHEMATICA
Table[n! * (n-9)^2*(n-8)^2*(n-7)*(n-6)*(n-5)*(n-4)*(n-3)*(n-2)*(9*n^4 - 270*n^3 + 2967*n^2 - 14098*n + 24352)/2106910310400, {n, 10, 25}] (* Vaclav Kotesovec, Jul 25 2014 *)
PROG
(Maxima) A055321(n) := block(
A055314(n, 9)
)$
for n : 10 thru 25 do
print(A055321(n), " ") ; /* R. J. Mathar, Mar 06 2012 */
(PARI) A055321(n)={binomial(n, 9)*sum(i=0, n-=9, (-1)^i*binomial(n, i)*i^(n+7))*(-1)^n} /* or: Stirling2(n-2, n-9)*n!/9!, cf. A008277 */ /* M. F. Hasler, Mar 06 2012 */
(Magma) [Factorial(n)*(n-9)^2*(n-8)^2*(n-7)*(n-6)*(n-5)*(n-4)*(n-3)*(n-2)*(9*n^4 - 270*n^3 + 2967*n^2 - 14098*n + 24352)/2106910310400: n in [10..25]]; // Vincenzo Librandi, Jul 25 2014
CROSSREFS
Column 9 of A055314.
Sequence in context: A203695 A181017 A360213 * A092300 A375539 A048916
KEYWORD
nonn
AUTHOR
Christian G. Bower, May 11 2000
STATUS
approved