OFFSET
0,4
COMMENTS
This is the labeled version of A027416 where the pertinent definitions can be found.
LINKS
N. J. A. Sloane, Illustration of initial terms
FORMULA
EXAMPLE
a(6) = 486. In the illustrations by Sloane found in the link above, for n = 6, there are A027416(3) = 3 trees with a centroid: the third, fourth and fifth trees shown. They have 360, 120, and 6 labelings respectively. 360 + 120 + 6 = 486.
MATHEMATICA
Prepend[Table[If[EvenQ[n], n^(n - 2) - Binomial[n, n/2] (n/2)^(n - 2)/2, n^(n - 2)], {n, 1, 17}], 0]
CROSSREFS
KEYWORD
nonn
AUTHOR
Geoffrey Critzer, Jul 31 2022
STATUS
approved