OFFSET
1,4
COMMENTS
It is conjectured that a(n)=o(n).
LINKS
Kaisa Matomäki, Maksym Radziwiłł and Terence Tao, An averaged form of Chowla's conjecture, Algebra & Number Theory, Vol. 9, No. 9 (2015), pp. 2167-2196.
MATHEMATICA
a[n_] := Sum[(-1)^(PrimeOmega[k] + PrimeOmega[k + 1]), {k, 1, n}]; Array[a, 100] (* Amiram Eldar, Nov 11 2021 *)
PROG
(PARI) a(n)=sum(k=1, n, (-1)^bigomega(k)*(-1)^bigomega(k+1))
CROSSREFS
KEYWORD
sign
AUTHOR
Benoit Cloitre, Nov 11 2021
STATUS
approved