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.

A117001 Sum_{d|n, sqrt(n) < d <= n} Jacobi(2,d)*d - Sum_{d|n, 1 <= d < sqrt(n)} Jacobi(2,d)*d.

Original entry on oeis.org

0, -1, -4, -1, -6, -4, 6, -1, 8, -6, -12, 2, -14, 6, 12, -1, 16, 11, -20, -6, -12, -12, 22, 2, 24, -14, -16, 6, -30, 22, 30, -1, 24, 16, -24, 11, -38, -20, 28, 4, 40, -12, -44, -12, -14, 22, 46, 2, 48, 29, -32, -14, -54, -16, 48, -8, 40, -30, -60, 22, -62, 30, 46, -1, 56, 24, -68, 16, -44, -38, 70, 11, 72, -38, -28, -20, -96, 28
Offset: 1

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Author

N. J. A. Sloane, Apr 15 2006

Keywords

References

  • H. J. S. Smith, Report on the Theory of Numbers, reprinted in Vol. 1 of his Collected Math. Papers, Chelsea, NY, 1979, see p. 323.

Crossrefs

Cf. A117000.

Programs

  • Maple
    with(numtheory); A117001:=proc(n) local d,t1,t2; t1:=0; t2:=0; for d from 1 to n do if n mod d = 0 then if d^2>n then t1:=t1+jacobi(2,d)*d; fi; if d^2
    				
  • Mathematica
    a[n_] := Sum[Which[Sqrt[n]Jean-François Alcover, Feb 17 2023 *)