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.

A354358 Möbius transform of A124859.

Original entry on oeis.org

1, 1, 1, 4, 1, 1, 1, 24, 4, 1, 1, 4, 1, 1, 1, 180, 1, 4, 1, 4, 1, 1, 1, 24, 4, 1, 24, 4, 1, 1, 1, 2100, 1, 1, 1, 16, 1, 1, 1, 24, 1, 1, 1, 4, 4, 1, 1, 180, 4, 4, 1, 4, 1, 24, 1, 24, 1, 1, 1, 4, 1, 1, 4, 27720, 1, 1, 1, 4, 1, 1, 1, 96, 1, 1, 4, 4, 1, 1, 1, 180, 180, 1, 1, 4, 1, 1, 1, 24, 1, 4, 1, 4, 1, 1, 1, 2100
Offset: 1

Views

Author

Antti Karttunen, Jun 05 2022

Keywords

Comments

Multiplicative because A124859 is.

Crossrefs

Programs

  • Mathematica
    primorial[n_] := Product[Prime[i], {i, 1, n}]; primorial[0] = 1; f[p_, e_] := primorial[e] - primorial[e-1]; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* Amiram Eldar, Jan 07 2023 *)
  • PARI
    A124859(n) = { my(f=factor(n)); for(k=1, #f~, f[k, 1] = prod(j=1, f[k, 2], prime(j)); f[k, 2] = 1); factorback(f); }; \\ From A124859
    A354358(n) = sumdiv(n,d,moebius(n/d)*A124859(d));

Formula

a(n) = Sum_{d|n} A008683(n/d) * A124859(d).
Multiplicative with a(p^e) = primorial(e) - primorial(e-1). - Sebastian Karlsson, Jul 30 2022