A124579 Number of natural numbers less than n which have identical Moebius mu values.

0, 0, 1, 0, 2, 1, 3, 1, 2, 2, 4, 3, 5, 3, 4, 4, 6, 5, 7, 6, 5, 6, 8, 7, 8, 7, 9, 10, 9, 10, 11, 11, 8, 9, 10, 12, 12, 11, 12, 13, 13, 14, 15, 14, 15, 13, 16, 16, 17, 18, 14, 19, 17, 20, 15, 21, 16, 17, 18, 22, 19, 18, 23, 24, 19, 20, 21, 25, 20, 22, 23, 26, 24, 21, 27, 28, 22, 25, 26, 29

Offset

1,5

Links

Table of n, a(n) for n=1..80.

Example

a(10) = 2 because in the first nine integers less than 10, mu(1) = mu(6) = mu(10).

Mathematica

a[n_] := a[n] = MoebiusMu@n; f[n_] := Count[a /@ Range[n - 1], a@n]; Array[f, 80]
With[{mu=MoebiusMu[Range[80]]}, Table[Count[Take[mu, n], _?(#==MoebiusMu[ n+1]&)], {n, 0, Length[mu]}]] (* Harvey P. Dale, Aug 18 2016 *)

Crossrefs

Cf. A124580.

Cf. A008683, A002321.

Sequence in context: A102862 A029331 A037269 * A035306 A101691 A349445

Adjacent sequences: A124576 A124577 A124578 * A124580 A124581 A124582

Keyword

nonn

Author

Robert G. Wilson v, Nov 05 2006

Status

approved