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.

A187487 Numerator of n minus n-th harmonic number.

Original entry on oeis.org

0, 1, 7, 23, 163, 71, 617, 1479, 15551, 17819, 221209, 246619, 3538687, 3873307, 4209643, 9094961, 166145857, 59239139, 1199057081, 254554945, 89778475, 94716499, 2292289173, 7218943253, 189040347533
Offset: 1

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Author

Alonso del Arte, Mar 10 2011

Keywords

Crossrefs

Denominators are in A002805.
Cf. A001008 (numerators of the harmonic numbers). Adding this sequence to that sequence gives A102928.

Programs

  • Maple
    f:=n -> numer(n - harmonic(n)):map(f, [$1..100]); # Robert Israel, Apr 26 2021
  • Mathematica
    Numerator[Table[n - HarmonicNumber[n], {n, 25}]]
  • PARI
    a(n) = numerator(n - sum(i=1, n, 1/i)); \\ Michel Marcus, Apr 26 2021

Formula

a(n) = n - Sum_{i = 1..n} 1/i.
a(n) = Sum_{i = 2..n} (i - 1)/i.