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.

A343282 Number of ordered 5-tuples (v,w, x, y, z) with gcd(v, w, x, y, z) = 1 and 1 <= {v, w, x, y, z} <= 10^n.

Original entry on oeis.org

1, 96601, 9645718621, 964407482028001, 96438925911789115351, 9643875373658964992585011, 964387358678775616636890654841, 96438734235127451288511508421855851, 9643873406165059293451290072800801506621
Offset: 0

Views

Author

Karl-Heinz Hofmann, Apr 10 2021

Keywords

References

  • Joachim von zur Gathen and Jürgen Gerhard, Modern Computer Algebra, Cambridge University Press, Second Edition 2003, pp. 53-54.

Crossrefs

Related counts of k-tuples:
triples: A071778, A342935, A342841;
quadruples: A082540, A343527, A343193;
5-tuples: A343282;
6-tuples: A343978, A344038. - N. J. A. Sloane, Jun 13 2021

Programs

  • Python
    from labmath import mobius
    def A343282(n): return sum(mobius(k)*(10**n//k)**5 for k in range(1, 10**n+1))

Formula

Lim_{n->infinity} a(n)/10^(5*n) = 1/zeta(5) = A343308.
a(n) = A082544(10^n). - Chai Wah Wu, Apr 11 2021

Extensions

Edited by N. J. A. Sloane, Jun 13 2021