A290246 Prime numbers that are common indices to both prime Lucas and prime Wagstaff numbers.

5, 7, 11, 13, 17, 19, 31, 61, 79, 313, 10691

Offset: 1

Author

Amiram Eldar, Jul 24 2017

Keywords

• hard
• nonn
• more

Comments

Prime numbers p such that Lucas(p) and (2^p + 1)/3 are both primes.

Intersection of A000978 and A001606.

Crossrefs

Cf. A000978, A001606, A080327.

Programs

Mathematica

seq = {}; wagstaff[n_] := (2^n + 1)/3; Do[p = Prime[n]; If[PrimeQ[LucasL[p]] && PrimeQ[wagstaff[p]], AppendTo[seq, p]], {n, 1, 1304}]; seq