

A238714


Final divisor of A238529(n).


1



2, 3, 4, 5, 5, 7, 2, 3, 3, 11, 5, 13, 5, 7, 8, 17, 2, 19, 2, 10, 3, 23, 5, 5, 11, 9, 5, 29, 10, 31, 2, 5, 7, 11, 5, 37, 17, 7, 7, 41, 5, 43, 5, 11, 10, 47, 4, 7, 2, 11, 17, 53, 3, 7, 4, 13, 9, 59, 12, 61, 29, 11, 4, 11, 2, 67, 5, 17, 14, 71, 12, 73, 11, 3, 7, 5, 5
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

2,1


COMMENTS

Conjecture: Every integer greater than 1, except 6, is an element of the sequence.


LINKS



EXAMPLE

a(8) = 2, because 8 mod sopfr(8) = 8 mod 6 = 2, and 2 mod sopfr(2) = 2 mod 2 = 0, and 2 is the last divisor used.
a(21) = 10, because 21 mod sopfr(21) = 21 mod 10 = 1, and 10 is the last divisor used.


PROG

(Python)
def primfacs(n):
i = 2
primfac = []
while i * i <= n:
while n % i == 0:
primfac.append(i)
n //= i
i += 1
if n > 1:
primfac.append(n)
return primfac
def sopfr(n):
plist = primfacs(n)
l = len(plist)
s = 0
while l > 0:
s += plist[l  1]
l = 1
return s
n = 2
max = 1000
lst = []
while n <= max:
rem = n
while rem > 1:
last = sopfr(rem)
rem = rem % last
lst.append(last)
n += 1
print(lst)


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



