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A067195
Numbers n such that M(n) = Sum_{i=1..n} mu(sigma(i)) where M(n) is the Mertens function A002321(n).
1
1, 2, 4, 30, 33, 38, 42, 45, 47, 48, 57, 59, 60, 64, 66, 69, 77, 82, 85, 104, 106, 118, 121, 194, 196, 201, 285, 287, 288, 290, 465, 467, 468, 470, 499, 500, 510, 610, 614, 626, 628, 631, 632, 642, 718, 723, 724, 785, 793, 798, 811, 812, 814, 823, 824, 825, 838
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
Sequence in context: A289776 A290169 A232173 * A080230 A084914 A058779
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Feb 19 2002
STATUS
approved