A163760 Exactly four distinct primes occur as substrings of the digits of n.

113, 131, 179, 197, 223, 231, 233, 235, 239, 253, 257, 271, 273, 283, 293, 297, 311, 313, 337, 347, 353, 359, 367, 371, 372, 375, 397, 431, 437, 473, 479, 531, 532, 547, 571, 573, 593, 597, 613, 617, 653, 713, 719, 723, 731, 732, 733, 735, 737, 739, 743