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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.

A306694 a(n) is the denominator of log(A014963(n))/log(n) if n > 1 and a(1) = 1.

Original entry on oeis.org

1, 1, 1, 2, 1, 1, 1, 3, 2, 1, 1, 1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 3, 1, 1, 1, 1, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 6, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2
Offset: 1

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Author

Mats Granvik, Mar 05 2019

Keywords

Comments

Log(A112624(n)) is the inverse Möbius transform of log(a(n)).

Crossrefs

Programs

  • Maple
    with(numtheory): pexp := n -> ifactors(n)[2][1][2]:
    a := n -> if nops(factorset(n)) = 1 then pexp(n) else 1 fi:
    seq(a(n), n=1..101); # Peter Luschny, Mar 19 2019
  • Mathematica
    Table[Denominator[FullSimplify[MangoldtLambda[n]/Log[n]]], {n, 1, 101}]
  • PARI
    A306694(n) = if((n=isprimepower(n))>0,n,1); \\ Antti Karttunen, Nov 17 2019
  • Sage
    def a(n):
        F = n.factor()
        return 1 if len(F) != 1 else F[0][1]
    print([a(n) for n in (1..101)]) # Peter Luschny, Mar 18 2019
    

Formula

If n is a prime power (in the sense of A246655) then a(n) is the exponent of this prime and otherwise a(n) is 1. - Peter Luschny, Mar 18 2019
Dirichlet generating function: zeta(s) + Sum_{n>=1} n*primezeta((n + 1)*s). - Mats Granvik, Mar 24 2019

Extensions

Data section extended up to term a(121) by Antti Karttunen, Nov 17 2019