A038869 Twin primes n and n-2 where 2n-1 is also prime.

7, 19, 31, 139, 199, 229, 271, 601, 619, 661, 811, 829, 1279, 1429, 1609, 2029, 2089, 2131, 2311, 2551, 2791, 3169, 3331, 3391, 3529, 3769, 4051, 4159, 4231, 4261, 4339, 4639, 4801, 5419, 5479, 5659, 5851, 6271, 6301, 6361, 6691, 6961, 7561, 7951, 8539