A081247 Number of numbers 1<=k<=n with mu(k+n)=mu(k), where mu=A008683 (Moebius function).

0, 0, 1, 2, 3, 1, 0, 5, 4, 3, 3, 7, 2, 4, 4, 10, 3, 6, 5, 12, 4, 3, 6, 16, 9, 6, 7, 13, 10, 10, 7, 16, 6, 9, 8, 25, 9, 9, 10, 22, 13, 13, 12, 19, 10, 9, 16, 29, 10, 16, 14, 24, 10, 21, 17, 31, 9, 13, 20, 37, 16, 14, 18, 30, 18, 20, 21, 35, 13, 16, 27, 49, 21, 15, 13, 42, 22, 25, 19, 39, 26

Offset

1,4

Links

Table of n, a(n) for n=1..81.

Example

n=10: mu(3+10)=mu(3)=-1, mu(7+10)=mu(7)=-1, mu(8+10)=mu(8)=0 and mu(k+10)<>mu(k) for k in {1,2,4,5,6,8,9}, therefore a(10)=3.

Crossrefs

Cf. A081248.

Sequence in context: A193535 A332645 A344855 * A298753 A173050 A172380

Adjacent sequences: A081244 A081245 A081246 * A081248 A081249 A081250

Keyword

nonn

Author

Reinhard Zumkeller, Mar 12 2003

Status

approved