OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
FORMULA
Lim_{n -> infinity} abs(a(n))/n = C = 0.30684(3)....
MATHEMATICA
Table[ Sum[(-1)^ Mod[n, k], {k, 1, n}], {n, 1, 81} ]
PROG
(PARI) a(n)=sum(k=1, n, (-1)^(n%k))
CROSSREFS
KEYWORD
sign
AUTHOR
Benoit Cloitre, Aug 10 2002
STATUS
approved