A085412 Numbers n such that concatenation of prime[n] and first digit of prime[n] is prime.

6, 8, 11, 12, 22, 27, 29, 36, 37, 42, 44, 67, 68, 71, 72, 73, 74, 75, 76, 133, 134, 138, 157, 160, 161, 162, 163, 164, 166, 169, 172, 174, 175, 179, 180, 187, 197, 204, 207, 210, 232, 235, 237, 247, 249, 251, 254, 261, 263, 264, 269, 272, 278, 282, 285, 287, 303