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.

A346202 a(n) = L(n)^2, where L is Liouville's function.

Original entry on oeis.org

1, 0, 1, 0, 1, 0, 1, 4, 1, 0, 1, 4, 9, 4, 1, 0, 1, 4, 9, 16, 9, 4, 9, 4, 1, 0, 1, 4, 9, 16, 25, 36, 25, 16, 9, 4, 9, 4, 1, 0, 1, 4, 9, 16, 25, 16, 25, 36, 25, 36, 25, 36, 49, 36, 25, 16, 9, 4, 9, 4, 9, 4, 9, 4, 1, 4, 9, 16, 9, 16, 25, 36, 49, 36, 49, 64, 49
Offset: 1

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Author

Mats Granvik, Jul 10 2021

Keywords

Comments

The Riemann Hypothesis is equivalent to the statement that, for every fixed eps > 0, lim_{n->oo} (L(n) / n^(eps + 1/2)) = 0.

References

  • Peter Borwein, Stephen Choi, Brendan Rooney, and Andrea Weirathmueller, The Riemann Hypothesis: A Resource for the Afficionado and Virtuoso Alike, 2007, page 6, Theorem 1.2.

Crossrefs

Cf. A002819, A008836, A028488 (positions of zeros).

Programs

  • Maple
    L:= proc(n) option remember; `if`(n<1, 0,
         (-1)^numtheory[bigomega](n)+L(n-1))
        end:
    a:= n-> L(n)^2:
    seq(a(n), n=1..77);  # Alois P. Heinz, Jul 28 2021
  • Mathematica
    Table[Sum[LiouvilleLambda[n], {n, 1, nn}]^2, {nn, 1, 77}]
  • PARI
    a008836(n) = (-1)^bigomega(n) \\ after Charles R Greathouse IV in A008836
    a(n) = sum(i=1, n, sum(j=1, n, a008836(i)*a008836(j))) \\ Felix Fröhlich, Jul 10 2021
    
  • Python
    from functools import reduce
    from operator import ixor
    from sympy import factorint
    def A346202(n): return sum(-1 if reduce(ixor, factorint(i).values(),0)&1 else 1 for i in range(1,n+1))**2 # Chai Wah Wu, Dec 20 2022

Formula

a(n) = Sum_{i=1..n} Sum_{j=1..n} A008836(i)*A008836(j).
a(n) = A002819(n)^2. - Ilya Gutkovskiy, Jul 10 2021