OFFSET
1,3
REFERENCES
F. Bergeron, G. Labelle and P. Leroux, Combinatorial Species and Tree-Like Structures, Cambridge, 1998, p. 68 (2.1.37).
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..230
D. E. Knuth, A recurrence related to trees, Proc. Amer. Math. Soc. 105 (1989), 335-349. Reprinted as Chapter 39 of Selected Papers on Discrete Mathematics by D. E. Knuth.
Thorsten Weist, On the Euler characteristic of Kronecker moduli spaces, arXiv preprint arXiv:1203.2740 [math.RT], 2012. Cor. 5.3, k=1. But offset 0.
FORMULA
a(n) = n^(n-2)*(n-1)!.
MATHEMATICA
Table[n!*n^(n-3), {n, 1, 20}] (* G. C. Greubel, May 29 2019 *)
PROG
(PARI) a(n) = n^(n-2)*(n-1)!; \\ Michel Marcus, May 29 2019
(Magma) [n^(n-3)*Factorial(n): n in [1..20]]; // G. C. Greubel, May 29 2019
(Sage) [n^(n-3)*factorial(n) for n in (1..20)] # G. C. Greubel, May 29 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Christian G. Bower, Dec 13 2001
EXTENSIONS
Knuth reference from David Callan, Feb 07 2004
STATUS
approved