A070285 a(n) = n^(n-2) * (n-1)^(n-1).

1, 12, 432, 32000, 4050000, 784147392, 215886856192, 80244904034304, 38742048900000000, 23579476910000000000, 17665746626579203620864, 15979082092619945289449472, 17171174753799627467382181888, 21626132883476724540000000000000, 31553580184752881664000000000000000

Offset: 2

Author

Sharon Sela (sharonsela(AT)hotmail.com), May 10 2002

Keywords

• nonn

Comments

Number of spanning trees in the bipartite graph K(n,n-1).

References

• J. J. Sylvester, On the change of systems of independent variables, Quarterly Journal of Mathematics, i. (1857), pp. 42-56; Collected Mathematical Papers, Volume 2, Cambridge (1908), pp. 65-85, see page 76.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 2..100

Crossrefs

Cf. A068087.

Programs

Magma

[n^(n-2) * (n-1)^(n-1): n in [2..20]]; // Vincenzo Librandi, Mar 04 2014

Maple

A070285:=n->n^(n-2) * (n-1)^(n-1); seq(A070285(n), n=2..15); # Wesley Ivan Hurt, Feb 26 2014

Mathematica

Table[n^(n - 2)*(n - 1)^(n - 1), {n, 2, 15}]

Extensions

Edited by Robert G. Wilson v, May 14 2002

More terms from Vincenzo Librandi, Mar 04 2014