A023241 Numbers n such that n remains prime through 2 iterations of function f(x) = x + 6.

5, 7, 11, 17, 31, 41, 47, 61, 67, 97, 101, 151, 167, 227, 251, 257, 271, 347, 367, 557, 587, 601, 607, 641, 647, 727, 941, 971, 1091, 1097, 1117, 1181, 1217, 1277, 1291, 1361, 1427, 1447, 1481, 1487, 1601, 1607, 1657, 1741, 1747, 1777, 1861, 1867, 1901, 1987