%I #14 Mar 19 2024 03:17:24

%S 122,127,128,142,5233

%N Numbers k such that A068340(k)=+/-2.

%C Any subsequent terms are > 10^12. - _Lucas A. Brown_, Mar 18 2024

%H Lucas A. Brown, <a href="https://github.com/lucasaugustus/oeis/blob/main/A076542.py">Python program</a>.

%o (PARI) isok(k) = abs(sum(i=1, k, i*moebius(i))) == 2; \\ _Michel Marcus_, Jan 14 2023

%Y Cf. A068340, A076542, A077031, A077032, A077033.

%K nonn,more,hard

%O 1,1

%A _Zak Seidov_, Oct 21 2002