OFFSET
1,2
COMMENTS
b(n) was used by Niven in the 1970's for an alternative proof of the divergence of the sum of reciprocals of the primes.
LINKS
Ivan Niven, A Proof of the Divergence of sum 1/p, The American Mathematical Monthly, Vol. 78, No. 3 (Mar., 1971), pp. 272-273.
PROG
(PARI) a(n)=denominator(sum(k=1, n, issquarefree(k)/k))
CROSSREFS
KEYWORD
easy,frac,nonn
AUTHOR
_Benoit Cloitre_, Aug 21 2002
STATUS
approved