A023265 Numbers n such that n remains prime through 2 iterations of function f(x) = 9x + 2.

3, 11, 19, 31, 103, 109, 113, 131, 151, 173, 179, 239, 283, 313, 491, 521, 599, 619, 733, 739, 773, 929, 1019, 1103, 1361, 1439, 1481, 1621, 1709, 1741, 1831, 1993, 2083, 2153, 2293, 2411, 2549, 2551, 2593, 2689, 2741, 2819, 2843, 2969, 3001, 3623, 3931, 4001