A285337 a(n) = denominator of A065642(n)/n.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 4, 1, 1, 1, 1, 3, 1, 1, 8, 1, 5, 1, 1, 1, 3, 1, 4, 1, 1, 1, 2, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 5, 1, 1, 1, 1, 4, 1, 1, 1, 2, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 8, 1, 7, 1, 5, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 1, 4

Offset: 1

Author

Antti Karttunen, Apr 19 2017

Keywords

• nonn
• frac

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A065642, A285100 (positions of ones), A284342 (positions of terms > 1).

Cf. A285336 for the numerator.

Programs

Python

from sympy import primefactors, prod, Integer
def a007947(n): return 1 if n<2 else prod(primefactors(n))
def a065642(n):
    if n==1: return 1
    r=a007947(n)
    n += r
    while a007947(n)!=r:
        n+=r
    return n
def a(n): return (a065642(n)/Integer(n)).denominator # Indranil Ghosh, Apr 20 2017

Scheme

(define (A285337 n) (denominator (/ (A065642 n) n)))