OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..3321
MATHEMATICA
Sum[Plus @@ GCD @@@ KSubsets[Range[n], m], {m, n}] (* or *)
Table[Sum[Plus@@(EulerPhi[Divisors[k]] 2^(k/Divisors[k]))/2, {k, n}], {n, 42}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Wouter Meeussen, Nov 30 2001
STATUS
approved