OFFSET
4,1
LINKS
V. I. Rodionov, On the number of labeled acyclic digraphs, Discr. Math. 105 (1-3) (1992), 319-321.
FORMULA
a(n) = (n-3)*(n-2)*(n-1)*n*(n^8 - 26*n^6 - 60*n^5 + 131*n^4 + 1200*n^3 + 3374*n^2 - 4140*n - 44640)/720. - Vaclav Kotesovec, Apr 11 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 04 2009
EXTENSIONS
More terms from Vaclav Kotesovec, Apr 11 2020
Offset changed to n=4 by Petros Hadjicostas, Apr 11 2020
STATUS
approved