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.

A370297 Inverse Moebius transform of A322328.

Original entry on oeis.org

1, 5, 5, 13, 5, 25, 5, 25, 13, 25, 5, 65, 5, 25, 25, 41, 5, 65, 5, 65, 25, 25, 5, 125, 13, 25, 25, 65, 5, 125, 5, 61, 25, 25, 25, 169, 5, 25, 25, 125, 5, 125, 5, 65, 65, 25, 5, 205, 13, 65, 25, 65, 5, 125, 25, 125, 25, 25, 5, 325, 5, 25, 65, 85, 25, 125, 5, 65, 25, 125, 5, 325
Offset: 1

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Author

Werner Schulte, Feb 14 2024

Keywords

Crossrefs

Programs

  • Mathematica
    f[p_, e_] := 2*e^2 + 2*e + 1; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* Amiram Eldar, Feb 14 2024 *)
  • PARI
    a(n) = factorback(apply(e->1+2*e*(e+1), factor(n)[,2]))

Formula

Multiplicative with a(p^e) = 1 + 2*e*(e+1) for prime p and e >= 0.
Dirichlet g.f.: (zeta(s))^5 / (zeta(2*s))^2.
Dirichlet convolution of A034444 and A048691.
Dirichlet inverse sequence b(n) for n > 0 is multiplicative with b(p) = -5 and b(p^e) = (-1)^e * (8*e-4) for prime p and e > 1.