A368642 - OEIS

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A368642

a(n) = Sum_{k=1..n} mu(k)^2 * ceiling(n/k), where mu is the Möbius function (A008683).

1, 3, 6, 8, 11, 14, 19, 21, 23, 26, 31, 33, 38, 41, 46, 50, 53, 55, 60, 62, 67, 72, 77, 79, 83, 86, 90, 92, 97, 100, 109, 111, 114, 119, 124, 128, 133, 136, 141, 145, 150, 153, 162, 164, 168, 173, 178, 180, 184, 186, 191, 195, 200, 202, 207, 211, 216, 221, 226, 228

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..60.

FORMULA

a(n) = A013928(n) + A008966(n) + A064608(n) - A034444(n).

MATHEMATICA

Table[Sum[MoebiusMu[k]^2*Ceiling[n/k], {k, n}], {n, 100}]

CROSSREFS

Cf. A008683 (mu), A008966, A013928, A034444, A064608.

Sequence in context: A362882 A265898 A133869 * A356395 A276573 A085197

Adjacent sequences: A368639 A368640 A368641 * A368643 A368644 A368645

KEYWORD

nonn,easy

AUTHOR

Wesley Ivan Hurt, Jan 01 2024

STATUS

approved