OFFSET
1,3
COMMENTS
Suggested by Eq. (80) of (Maia and Mendez, 2008).
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..453
M. Maia and M. Mendez, On the arithmetic product of combinatorial species, Discr. Math., 308 (2008), 5407-5427.
MAPLE
with(numtheory);
f:=proc(n) local d; option remember;
if n=1 then 1
else add( ((n-1)!/(d!*((n-1)/d)!))*((n-1)/d)*f(d), d in divisors(n-1)); fi;
end;
[seq(f(n), n=1..40)];
MATHEMATICA
f[n_] := Block[{m = n - 1}, Plus @@ Flatten[((m!/(#!*(m/#)!)) (m/#)*f@#) & /@ Divisors@m]]; f[1] = 1; Array[f, 25] (* Robert G. Wilson v, Dec 10 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Dec 09 2017
STATUS
approved