cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A091555 Partial sums of Mertens's function (A002321).

Original entry on oeis.org

1, 1, 0, -1, -3, -4, -6, -8, -10, -11, -13, -15, -18, -20, -21, -22, -24, -26, -29, -32, -34, -35, -37, -39, -41, -42, -43, -44, -46, -49, -53, -57, -60, -62, -63, -64, -66, -67, -67, -67, -68, -70, -73, -76, -79, -81, -84, -87, -90, -93, -95, -97, -100, -103, -105, -107
Offset: 1

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Author

Jon Perry, Mar 04 2004

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Sum[MoebiusMu[k] (n - k + 1), {k, 1, n}], {n , 1, 56}] (* Indranil Ghosh, Mar 16 2017 *)
    Accumulate[Table[Sum[MoebiusMu[k], {k, 1, n}], {n, 1, 100}]] (* Vaclav Kotesovec, Nov 30 2024 *)
  • PARI
    for(n=1, 56, print1(sum(k=1, n, moebius(k) * (n - k + 1)),", ")) \\ Indranil Ghosh, Mar 16 2017

Formula

a(n) = Sum_{k=1..n} mu(k)*(n-k+1) where mu=A008683, the Moebius function. - Reinhard Zumkeller, Nov 06 2006
G.f.: (1/(1 - x)^2)*Sum_{k>=1} mu(k)*x^k. - Ilya Gutkovskiy, Mar 11 2018

Extensions

More terms from Reinhard Zumkeller, Nov 06 2006