A023209 Numbers n such that n and 3n + 4 both prime.

3, 5, 11, 13, 19, 23, 31, 41, 53, 59, 73, 79, 89, 101, 103, 109, 131, 139, 151, 173, 179, 181, 191, 199, 223, 229, 241, 251, 269, 283, 293, 311, 331, 349, 353, 373, 383, 389, 409, 431, 433, 439, 509, 521, 541, 563, 593, 599, 619, 643, 661, 683, 709, 719, 733, 739, 761