OFFSET
2,2
COMMENTS
For n > 2, the connected domination number of the n-triangular graph is n-2.
LINKS
G. C. Greubel, Table of n, a(n) for n = 2..385
Eric Weisstein's World of Mathematics, Connected Dominating Set.
Eric Weisstein's World of Mathematics, Triangular Graph.
FORMULA
a(2) = 1, a(n) = n*(n - 1)^(n - 3). - Detlef Meya, Jun 20 2024
E.g.f.: -(x/2)*((W(-x) + 1)^2 - 1 + x), where W(x) = Lambert W function. - G. C. Greubel, Mar 19 2025
MATHEMATICA
a[2] := 1; a[n_] := n*(n - 1)^(n - 3); Table[a[n], {n, 2, 19}] (* Detlef Meya, Jun 20 2024 *)
PROG
(Magma)
A373395:= func< n | n eq 2 select 1 else n*(n-1)^(n-3) >;
[A373395(n): n in [2..30]]; // G. C. Greubel, Mar 19 2025
(SageMath)
def A373395(n): return 1 if n==2 else n*(n-1)^(n-3)
print([A373395(n) for n in range(2, 31)]) # G. C. Greubel, Mar 19 2025
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric W. Weisstein, Jun 03 2024
EXTENSIONS
a(9) and beyond from Detlef Meya, Jun 20 2024
STATUS
approved
