ZIP codes of the form DRRRR and RRRRR (repdigit)

In a previous post I recalled a project I tried to do at zipinfo and zipdecode a list of prime near-repdigit ZIP codes. In 2004, I had noticed how, looking only at the prime subset, few ZIP codes of the form DRRRR or RRRRD seemed to exist, and originally planned to examine this.

However, a clearer look shows that in fact near-repdigit ZIP codes are more common that I imagined when I first re-did my work on zipdecode a couple of weeks ago. Thus, I have felt that to list them I will have to subdivide near-repdigit ZIP codes according to the form of the number.

This first installment will look at DRRRR-type near-repdigit ZIP codes, and in the process I will also look at true repdigit ZIP codes. When I first realised not all possible ZIP codes were in use – and the number actually in use for contiguous US addresses covered in zipdecode is fewer than even the 42,000 or so currently in use – I found these numbers interesting because of the coverage of palindromic prime ZIP codes by The Prime Pages and I wanted to look at other unusual codes – as well as prime postcodes here in Australia. I did a bit of work now deleted from the Prime Pages back in 2004, but for some reason felt I should re-do this.

ZIP Code	City	State	Notes
10000	Unassigned
11111
12222	Albany	New York	between Washington and Western Avenues Includes State University of New York campus
13333	East Springfield	New York	Northeast of Osego Lake
14444	Unassigned
15555	Quecreek	Pennsylvania	Shared with ZIP code 15561
16666	Osceola Mills	Pennsylvania	West of Phillsburg and State Game Reserve 33
17777	Watsontown	Pennsylvania	on Susquehanna River north of Harrisburg
18888	Unassigned
19999
20000
21111	Monkton	Maryland	north of Baltimore on I-83
22222	Unassigned (22222 was previously assigned to part of Arlington, Virginia)
23333
24444
25555	Prichard	West Virginia	on Kentucky border on Big Sandy River – a tributary of the Ohio River
26666	Unassigned
27777
28888
29999
30000
31111
32222	Jacksonville	Florida	south of 103rd Street, east of Cecil Commerce Center and north of Argyle Forest Boulevard.
33333	Unassigned
34444
35555	Fayette	Alabama	northwest of Tuscaloosa on Route 43 in county of same name
36666	Unassigned
37777	Louisville	Tennessee	on Tennessee River south of Knoxville
38888	Unassigned
39999
40000
41111
42222
43333	Lewistown	Ohio	in Logan County 5 kilometres from Indian Lake
44444	Newton Falls	Ohio	on the Mahoning River southeast of Warren in Trumbull County
45555	Unassigned
46666
47777
48888	Stanton	Michigan	in rural Montcalm County on state 66
49999	Unassigned
50000
51111	Sioux City	Iowa	Mostly Sioux City Gateway Airport, but north to Missouri River (where borders on South Sioux City, Nebraska) and east to I-29
52222	Deep River	Iowa	in Poweshiek County,about 75 kilometres (45 miles) from Iowa City.
53333	Unassigned
54444	Kempster	Wisconsin	in rural Langland County in north of state
55555	Unassigned		formerly assigned to Young America, Carver County, Minnesota
56666	Ponemah	Minnesota	in remote Beltrah County on Red Lake Indian Reservation
57777	Red Owl	South Dakota	in Meade County east of Rapid City
58888	Unassigned
59999
60000
61111	Loves Park	Illinois	in Winnebago County in northernmost part of state; part of Rockford statistical area
62222	Belleville	Illinois	on Missouri border in St. Clair County; most populous city south of Springfield in downstate Illinois
63333	Bellflower	Missouri	in Montgomery County on lower Missouri River
64444	Edgerton	Missouri	in rural Platte County on border with Kansas part of Kansas City metropolitan area
65555	Raymondville	Missouri	in Texas County in southern Ozarks
66666	Unassigned
67777
68888
69999
70000
71111	Bossier City	Louisiana	in Bossier Parish, part of Shreveport metropolitan area where second largest city
72222	Little Rock	Arkansas	city downtown directly south of Arkansas River
73333	Unassigned
74444	Moodys	Oklahoma	in Cherokee County in east of state
75555	Bivins	Texas	in Cass County on border with Arkansas and Louisiana
76666	Mertens	Texas	in Hill County in the north central part of the state
77777	Unassigned
78888
79999	El Paso	Texas	PO Boxes only
80000	Unassigned
81111
82222	Lance Creek	Wyoming	in Niobrara County in east of state
83333	Hailey	Idaho	in central mountains of state, seat of Blaine County famous as current home of 1980s tennis star Mats Wilander and birthplace of poet Ezra Pound
84444	Unassigned
85555
86666
87777
88888
89999
90000
91111
92222	Bard	California	in Imperial county on Arizona and Mexico border
93333	Unassigned
94444
95555	Orick	California	on North Coast in Humboldt County
96666	FPO	United States Navy	all ZIP codes from 96200 to 96699 are Pacific military
97777	Unassigned
98888
99999

Overall, thirty-three of ninety possible ZIP codes of the forms R_w and DR_w are in use, which is only marginally lower a proportion than for all possible US ZIPs and does not suggest near-repdigit ZIP codes are avoided – my mother said today they would be much easier to remember and that people would say them “one double one double one” for the (unassigned) repunit ZIP code. Only codes with repeated zeroes seem to be avoided, perhaps because most state capitals in the US are relatively small towns with a public service orientation much more pronounced than Canberra – for example Frankfort, Kentucky has only 25,000 of about 4,400,000 people in the state.