OFFSET
1,1
LINKS
Paolo P. Lava, Table of n, a(n) for n = 1..300
MAPLE
with(numtheory); P:=proc(q) local a, n, p; for n from 1 to q do
a:=n*add(op(2, p)/op(1, p), p=ifactors(n)[2]);
if isprime(a+n) and isprime(a-n) then print(n); fi;
od; end: P(10^5);
PROG
(Python)
from sympy import isprime, factorint
A229272 = []
for n in range(1, 10**5):
np = sum([int(n*e/p) for p, e in factorint(n).items()]) if n > 1 else 0
if isprime(np+n) and isprime(np-n):
A229272.append(n)
# Chai Wah Wu, Aug 21 2014
CROSSREFS
KEYWORD
nonn,changed
AUTHOR
Paolo P. Lava, Sep 18 2013
STATUS
approved