“ZIP code 69577 is not currently assigned by the US Postal Service to any city. Only about 43,000 of the 100,000 possible 5-digit ZIP codes are currently in use.”and similar sayings for ZIP codes 23333, 86453, 11113, 54342 and no doubt others that I cannot recall. My brother showed me the more user-friendly zipdecode where one could see why the ZIP code 69577 (the number of runs conceded by record-breaking Kent spin bowler “Tich” Freeman in his career) does not exist – if it did it would be in the remote Nebraska Panhandle. In fact no ZIP codes from 69400 to 69999 exist, probably owing to the economic decline of the Plains.
Back in 2004, I looked for near-repdigit prime ZIP codes of the forms RwD and DRw on zipdecode and was struck by how few there actually were relative to the possible ones. I did not count how many possible ZIP codes were but the number I found in use was no more than a handful.
This night, I decided to have a another look and publish my results. Even counting other forms of near-repdigit five-digit prime (RDRw, RRDRR, RwDR) I could find only the following twelve when I found 22229 was no longer used:
|10111||New York City||New York|
|11411||Cambria Heights||New York||a middle-class New York City neighbourhood|
|16111||Atlantic||Pennsylvania||in rural western Pennsylvania northeast of Youngstown, Ohio|
|33331||Fort Lauderdale||Florida||west of 142nd Avenue and 148th Avenue to 185th Way|
|38333||Eva||Tennessee||rural area of Benton County west of Nashville and on Kentucky Lake|
|44449||North Benton||Ohio||rural area of Mahoning County south of Berlin Lake and Route 62, due east of Akron.|
|77377||Tomball||Texas||Houston exurb in northwest of metropolitan area|
|77477||Stafford||Texas||Houston exurb near Sugar Land|
small village between Victoria and San Antonio Bay
|79999||El Paso||Texas||post office boxes only|
|94999||Petaluma||California||southern Napa Valley north of San Pablo Bay. Rural area of Sonoma County and major wine-growing area.|
|99929||Wrangel||Alaska||superhumid southeast Alaska not far from Ketchikan|