OFFSET
1,2
LINKS
Indranil Ghosh, Table of n, a(n) for n = 1..263 (terms < 5000)
MATHEMATICA
M[n_] := Sum[MoebiusMu[k], {k, n}]; Select[Range@ 838, Sum[MoebiusMu[DivisorSigma[1, i]], {i, #}] == M[#] &] (* Indranil Ghosh, Mar 16 2017 *)
PROG
(PARI) isok(n) = sum(i = 1, n, moebius(sigma(i))) == mertens(n); \\ Michel Marcus, Sep 24 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Feb 19 2002
STATUS
approved