OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
a(3)=108 is a term because 107 and 109 are primes and the sum of prime factors of 107, 108=2^2*3^3 and 109 is 107+2+2+3+3+3+109 = 229, which is prime.
MAPLE
P:= select(isprime, {seq(i, i=3..10^6, 2)}):
T:= map(`+`, P, 1) intersect map(`-`, P, 1):
filter:= proc(t) local s; isprime(2*t+add(s[1]*s[2], s=ifactors(t)[2])) end proc:
sort(convert(select(filter, T), list));
CROSSREFS
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Dec 27 2020
STATUS
approved