OFFSET
1,1
COMMENTS
Any subsequent terms are > 10^12. - Lucas A. Brown, Mar 18 2024
LINKS
Lucas A. Brown, Python program.
PROG
(PARI) isok(k) = abs(sum(i=1, k, i*moebius(i))) == 4; \\ Michel Marcus, Jan 14 2023
CROSSREFS
KEYWORD
nonn,more,hard
AUTHOR
Zak Seidov, Oct 21 2002
STATUS
approved