A067195 Numbers n such that M(n) = Sum_{i=1..n} mu(sigma(i)) where M(n) is the Mertens function A002321(n).

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

Cf. A000203, A008683.

Sequence in context: A289776 A290169 A232173 * A080230 A084914 A058779

Adjacent sequences: A067192 A067193 A067194 * A067196 A067197 A067198

Keyword

nonn

Author

Benoit Cloitre, Feb 19 2002

Status

approved