| 47.7º N, 117.5º W, approximation error box (in magenta), click to enlarge |
Monday, January 24, 2022
How not to communicate one's GPS location
Friday, January 21, 2022
Telephone puzzler
Local calls appeared to be getting through on our home-phone landline but not long-distance calls, as evidenced by a handful of instances over the course of a month. I was certain that the problem lay in some distant Bell relay device and that the technician likely wouldn't have to come into the house. I was wrong.
| Ekene, technician, connecting a new cable to a nearby Bell hub |
Monday, January 17, 2022
Friday, December 31, 2021
Saturday, December 25, 2021
Tuesday, December 21, 2021
Wildlife
| coyote under the streetlight, click to enlarge |
Thursday, December 16, 2021
YYZ
From high above my abode in south Weston, courtesy the latest version of Mathematica, a graphic representation of Canadian and U.S. flight paths yesterday that started or ended at nearby Toronto Pearson International Airport. Zooming in ...
Sunday, December 05, 2021
Weston Station
![]() |
| click to enlarge |
Roy Murray wrote an article on WestonWeb.ca about Castlepoint's "Weston Park" proposed development right beside Weston Station, pointing us to a YouTube video by Castlepoint Numa on the project. I watched it on December 2nd and noticed that the location of Weston Station had been moved southeast so as to appear much closer to Eglinton Ave. W. in Mount Dennis. So I decided to make a YouTube comment pointing that out: "There's a transit map at 0:50 to 0:55 where Weston Station pops up at an incorrect location. It's actually a good deal further northwest. Presumably the disingenuous placement is meant to convince the target of this propaganda piece of the station's proximity to the Eglinton Crosstown corridor."
![]() |
| click to enlarge |
Thursday, November 18, 2021
Pandigital palindromic sums
Two days ago Éric Angelini posted on MathFun:
234567898765432 + 1000000000000000 = 1234567898765432
... noting that (ignoring the arithmetic symbols) the concatenated 47 digits are a palindrome. Éric wondered about smaller palindromic sums where all ten digits are present ("pandigital" in the sense of A171102). Here are the 24 smallest:
12076 + 38354945 = 38367021
12076 + 83854945 = 83867021
12376 + 80854945 = 80867321
12876 + 30354945 = 30367821
13086 + 27254945 = 27268031
13086 + 72754945 = 72768031
13286 + 70754945 = 70768231
13786 + 20254945 = 20268731
21067 + 38354945 = 38376012
21067 + 83854945 = 83876012
21367 + 80854945 = 80876312
21867 + 30354945 = 30376812
23087 + 16154945 = 16178032
23087 + 61654945 = 61678032
23187 + 60654945 = 60678132
23687 + 10154945 = 10178632
31068 + 27254945 = 27286013
31068 + 72754945 = 72786013
31268 + 70754945 = 70786213
31768 + 20254945 = 20286713
32078 + 16154945 = 16187023
32078 + 61654945 = 61687023
32178 + 60654945 = 60687123
32678 + 10154945 = 10187623
Thursday, November 11, 2021
What a difference five months make
Five months ago, I showcased the then-ten-largest-known Leyland primes. Here's an update:
500973 (100207,99856) Gabor Levai Nov 2021
500702 (100263,98600) Gabor Levai Sep 2021
386642 (81650,54369) Yusuf AttarBashi Jun 2021
386561 (80565,62824) Hans Havermann Aug 2021
386548 (83747,41272) Hans Havermann Aug 2021
386434 (328574,15) Sergey Batalov May 2014
302858 (84181,3960) Hans Havermann Nov 2021
301815 (83278,4209) Hans Havermann Sep 2021
301763 (64431,48250) Hans Havermann Sep 2021
301716 (67237,30714) Hans Havermann Sep 2021

