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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

Tom Davis, Table of n, a(n) for n = 2..10001

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 = n / i

       i = i + 1

   if n > 1:

       primfac.append(n)

   return primfac

def sopfr(n):

   plist = list(primfacs(n))

   l = len(plist)

   s = 0

   while l > 0:

       s += plist[l - 1]

       l -= 1

   return s

n = 2

max = 1000

lst = list()

while n <= max:

   rem = n

   while rem > 1:

       last = sopfr(rem)

       rem = rem % last

   lst.append("%i" % last)

   n += 1

print lst

CROSSREFS

Cf. A238529.

Sequence in context: A017855 A051598 A086993 * A289311 A029908 A081758

Adjacent sequences:  A238711 A238712 A238713 * A238715 A238716 A238717

KEYWORD

nonn

AUTHOR

J. Stauduhar, Mar 03 2014

STATUS

approved

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Last modified July 17 18:41 EDT 2019. Contains 325109 sequences. (Running on oeis4.)