A081237 Numbers n with no k, 0<k<n, such that mu(n-k)=mu(n)=mu(n+k), where mu=A008683 (Moebius function).

1, 2, 3, 4, 6, 9, 15, 21

Offset

1,2

Comments

A081236(n)=0.

Conjecture: there are no more terms.

Next term, if one exists, exceeds 10000000000. [From Sean A. Irvine, Sep 08 2009]

Links

Table of n, a(n) for n=1..8.

Crossrefs

Sequence in context: A096824 A192488 A089797 * A022159 A022161 A287148

Adjacent sequences: A081234 A081235 A081236 * A081238 A081239 A081240

Keyword

nonn,more

Author

Reinhard Zumkeller, Mar 11 2003

Status

approved