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.

A088530 Denominator of bigomega(n)/omega(n).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 2, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 2, 2, 1, 1, 1, 2, 1, 1, 1, 3, 1, 1, 1, 1, 1, 3, 1, 2, 1, 1, 1, 1, 1, 2, 2, 1
Offset: 2

Views

Author

Cino Hilliard, Nov 16 2003

Keywords

Comments

a(n) is the denominator of A022559(n)/A000720(n). - Robert Israel, Jan 08 2024

Examples

			bigomega(24) / omega(24) = 4/2 = 2/1, so a(24) = 1.
		

Crossrefs

Cf. A001221, A001222, A000720, A022559, A070012, A070013, A070014, A088529 (gives the numerator).

Programs

  • Maple
    N:= 100:
    W:= ListTools:-PartialSums(map(numtheory:-bigomega,[$1..N])):
    seq(denom(W[i]/numtheory:-pi(i)),i=2..N); # Robert Israel, Jan 08 2024
  • Mathematica
    Table[Denominator[PrimeOmega[n]/PrimeNu[n]],{n,2,100}] (* Harvey P. Dale, Mar 22 2012 *)
  • PARI
    for(x=2,100,y=bigomega(x)/omega(x);print1(denominator(y)","))
    
  • Python
    from sympy import primefactors, Integer
    def bigomega(n): return 0 if n==1 else bigomega(Integer(n)/primefactors(n)[0]) + 1
    def omega(n): return Integer(len(primefactors(n)))
    def a(n): return (bigomega(n)/omega(n)).denominator
    print([a(n) for n in range(2, 51)]) # Indranil Ghosh, Jul 13 2017

Formula

Let B = number of prime divisors of n with multiplicity, O = number of distinct prime divisors of n. Then a(n) = denominator of B/O.