A175770 In the sequence of prime numbers, replace all the P digits by Q's and vice versa, where P and Q are 1 and 3.

2, 1, 5, 7, 33, 31, 37, 39, 21, 29, 13, 17, 43, 41, 47, 51, 59, 63, 67, 73, 71, 79, 81, 89, 97, 303, 301, 307, 309, 331, 327, 313, 317, 319, 349, 353, 357, 361, 367, 371, 379, 383, 393, 391, 397, 399, 233, 221, 227, 229, 211, 219, 243, 253, 257, 261, 269, 273, 277