A169984 Primes in carryless arithmetic mod 10 in which all digits except the rightmost are zero or five.

51, 52, 53, 54, 56, 57, 58, 59, 551, 553, 557, 559, 5051, 5053, 5057, 5059, 5501, 5503, 5507, 5509, 50051, 50053, 50057, 50059, 55001, 55003, 55007, 55009, 55551, 55553, 55557, 55559, 500501, 500503, 500507, 500509, 505001, 505003