A328704 Primes dividing nonzero terms in A002065.

3, 13, 61, 151, 211, 223, 739, 1009, 1531, 4363, 4513, 5503, 6277, 6397, 7753, 7873, 9463, 11353, 11587, 11677, 12007, 12241, 13669, 15061, 15391, 17509, 17791, 21157, 25243, 25747, 26959, 28351, 28411, 29641, 30553, 30727, 31873, 33289, 33469, 33997, 36343, 36721, 37117, 37201

Offset: 1

Author

Jianing Song, Oct 26 2019

Keywords

• nonn

Comments

Primes in A328703.

Sequence is infinite: it contains all prime factors of the numbers A002065(p), where p is any prime. Note that gcd(A002065(p), A002065(q)) = 1 for primes p != q. So the set of prime factors of {A002065(p) : p prime} is infinite.

Crossrefs

Cf. A002065, A328703.

Programs

PARI

v(n) = my(v=[0],k,flag=1); for(i=2, n+1, k=(v[#v]^2+v[#v]+1)%n; v=concat(v, k); for(j=1, i-1, if(v[j]==k, flag=0)); if(flag==0, break())); v
a(n) = isprime(n) && !(v(n)[#v(n)])