OFFSET
1,1
COMMENTS
It appears that the resulting primes are a subsequence of A112885. - Michel Marcus, Aug 16 2018
If p is a prime in this sequence, then prime(p)+p+1 is prime. Put k = p+1, then prime(p)+p+1 = prime(k-1)+k, and is prime, so is in A112885. Therefore the resulting primes of this sequence are a subsequence of A112885. - David James Sycamore, Aug 16 2018
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..10000
EXAMPLE
Prime(5)+5+1 = 11+5+1 = 17 therefore 5 is a member of the sequence, and is the first such prime, hence a(1) = 5.
MAPLE
N := 2000;
for X from 1 to N do
Z := ithprime(X);
P := Z+X+1;
if isprime(X) and isprime(P) then print(X);
end if
end do
MATHEMATICA
Select[Prime@ Range@ 300, PrimeQ[# + Prime[#] + 1] &] (* Giovanni Resta, Aug 16 2018 *)
PROG
(PARI) isok(p) = isprime(p) && isprime(prime(p) + p + 1); \\ Michel Marcus, Aug 16 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
David James Sycamore, Aug 10 2018
STATUS
approved