OFFSET
1,2
COMMENTS
The first 5 sums are: 1,4/3,35/24,257/168,11/7.
EXAMPLE
a(3)=24 because phi(1)*sigma(1)+phi(2)*sigma(2)+phi(3)*sigma(3)=1/(1*1)+1/(1*3)+1/(2*4)=35/24.
MAPLE
with(numtheory): a:=n->denom(sum(1/phi(k)/sigma(k), k=1..n)): seq(a(n), n=1..35);
CROSSREFS
KEYWORD
frac,nonn
AUTHOR
Emeric Deutsch, Mar 12 2005
STATUS
approved