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A285337
a(n) = denominator of A065642(n)/n.
4
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
1,12
LINKS
PROG
(Scheme) (define (A285337 n) (denominator (/ (A065642 n) n)))
(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
CROSSREFS
Cf. A065642, A285100 (positions of ones), A284342 (positions of terms > 1).
Cf. A285336 for the numerator.
Sequence in context: A319094 A069283 A319430 * A328457 A340827 A360119
KEYWORD
nonn,frac
AUTHOR
Antti Karttunen, Apr 19 2017
STATUS
approved