OFFSET
1,3
LINKS
Georg Fischer, Table of n, a(n) for n = 1..100
FORMULA
a(n) = n! * Sum_{d|n} (-1)^(n - d) / (d * (n/d)^d).
MAPLE
a:= n-> n!*add((-1)^(n-d)/(d*(n/d)^d), d=numtheory[divisors](n)):
seq(a(n), n=1..24); # Alois P. Heinz, Oct 30 2019
MATHEMATICA
nmax = 23; CoefficientList[Series[Sum[Log[1/(1 + (-x)^k/k)], {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]! // Rest
Table[n! Sum[(-1)^(n - d)/(d (n/d)^d), {d, Divisors[n]}], {n, 1, 23}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Oct 30 2019
STATUS
approved