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A319520
Starts of strictly increasing runs of 0's in Mertens's function A002321.
0
2, 39, 331, 422, 45371, 22898822, 871469945
OFFSET
1,1
COMMENTS
a(n) is always squarefree.
It is not known whether this sequence is infinite. Sequence A045882 is infinite but it appears that increasing runs of consecutive nonsquarefree numbers thin out very quickly. The requirement that the runs consist of 0's is much stronger and makes it uncertain whether this sequence is also infinite.
EXAMPLE
2 is a term because M(2) = 0.
39 is a term because M(39) = M(40) = 0.
331 is a term because M(331) = M(332) = M(333) = 0.
422 is a term because M(422) = ... = M(425) = 0.
45371 is a term because M(45371) = ... = M(45376) = 0.
MATHEMATICA
With[{s = Map[Boole[# == 0] &, Accumulate@ Array[MoebiusMu, 10^5]]}, Union@ Array[SequencePosition[s, ConstantArray[1, #]][[1, 1]] &, 5]] (* Michael De Vlieger, Sep 26 2018 *)
PROG
(PARI) M=S=R=0; for(n=1, oo, if(!M+=moebius(n), S||S=n, S, n-S>R&&print1(S", ")+R=n-S; S=0)) \\ M. F. Hasler, Nov 23 2018
CROSSREFS
Sequence in context: A086338 A329552 A042683 * A209632 A266863 A245053
KEYWORD
nonn,more
AUTHOR
Torlach Rush, Sep 21 2018
EXTENSIONS
a(6)-a(7) from Amiram Eldar, Sep 26 2018
STATUS
approved