A076369 a(n) = n + mu(n), where mu is the Moebius function (A008683).

2, 1, 2, 4, 4, 7, 6, 8, 9, 11, 10, 12, 12, 15, 16, 16, 16, 18, 18, 20, 22, 23, 22, 24, 25, 27, 27, 28, 28, 29, 30, 32, 34, 35, 36, 36, 36, 39, 40, 40, 40, 41, 42, 44, 45, 47, 46, 48, 49, 50, 52, 52, 52, 54, 56, 56, 58, 59, 58, 60, 60, 63, 63, 64, 66, 65, 66, 68, 70, 69, 70, 72

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

a(n) = n + mu(m) = A000027(n) + A008683(n).

a(n) = n iff n is not squarefree: a(A013929(k)) = A013929(k) and a(A005117(k)) <> A005117(k).

Mathematica

a[n_] := n + MoebiusMu[n]; Array[a, 100] (* Amiram Eldar, Apr 09 2025 *)

Prog

(PARI) a(n) = n + moebius(n); \\ Amiram Eldar, Apr 09 2025

Crossrefs

Cf. A000027, A005117, A008683, A013929, A063015, A076840.

Sequence in context: A134005 A132320 A353400 * A328790 A319773 A256188

Adjacent sequences: A076366 A076367 A076368 * A076370 A076371 A076372

Keyword

nonn,easy

Author

Reinhard Zumkeller and Labos Elemer, Oct 14 2002

Status

approved