OFFSET
1,5
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..10000
PROG
(Python)
from sympy import factorint
from operator import mul
def P(n):
f = factorint(n)
return sorted([f[i] for i in f])
def a046523(n):
x=1
while True:
if P(n) == P(x): return x
else: x+=1
def a072438(n):
f = factorint(n)
return 1 if n == 1 else reduce(mul, [1 if i%4==1 else i**f[i] for i in f])
def a(n): return a046523(n/a072438(n)) # Indranil Ghosh, May 09 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 08 2017
STATUS
approved