The first 11 million Kaprekar numbers

Just published. I won't know the answer to the appended question anytime soon.

Spoonful

David 'Honeyboy' Edwards died on Monday, so yesterday I listened to a bit of what I had of his in iTunes (mostly the Delta Bluesman album). One of the songs was Just a Spoonful, which brought me to list all of the 'Spoonful' covers that I had: about a dozen. Cream's short six-and-a-half-minute version from Fresh Cream played next and I was reminded that they had a long version on their Wheels of Fire double-album which, back in the day, I once owned. But the album was missing from my iTunes library, so I downloaded it — and am listening to it today. Catherine actually brought into our relationship the Fresh Cream album (along with The Incredible String Band's Wee Tam & The Big Huge), acquired back then from Kay Owen, her British cousin. Much appreciated music, even after all these years.

The largest base-24 left-truncatable prime

10594160686143126162708955915379656211582267119948391137176997290182218433

As previously aspired to, I have now replicated Martin Fuller's 2008 determination of all base-24 left-truncatable primes. I don't know if Martin thought to store the largest of these as part of his program, but I don't see it anywhere on the Net and more specifically not in the a-file for A103443, where it belongs. It's the 53-digit number {17, 22, 19, 14, 19, 15, 10, 3, 10, 7, 1, 13, 18, 13, 9, 22, 15, 22, 23, 15, 14, 3, 13, 3, 20, 19, 17, 10, 6, 1, 20, 17, 9, 2, 18, 15, 12, 10, 3, 21, 11, 8, 16, 15, 4, 4, 4, 15, 11, 11, 7, 10, 17}.

Bookends

Back on May 7, I created a 9 times 48969-digits-each, type-2 Belgian-numbers html-file to elegantly display solutions to Eric Angelini's second type of Self Belgian Numbers. On May 17, I published a list of thirteen type-2 Belgian primes plus six more probable primes, the largest composed of 27867 digits. By May 24, I had determined for what number-length (after length 1) all nine type-2 Belgian-number templates again produced solutions: length 1899283.

All that needed to be done now was to find all solutions to length 1899283 so that these might be as elegantly displayed as my initial length-48969 set. The calculation took about a week for each of the nine templates and, on July 31, I html-colourized the result. Only problem was, the numbers would not display properly in any of the browsers that I tried. The far-right digits did not align, even though all nine numbers have the same number of digits and they are rendered in a monospace font.

Thankfully, Firefox 6 has just been released and it did display the numbers correctly! The length-1899283 solutions turned out to be terms 3594728-3594736 of A107070 and because these nine solutions along with the first nine solutions form "bookends" to all the other solutions within the nine templates, that's what I ended up naming the over-80-MB file.

Next

9987, 10157, 10120, 10069, 9906, 10174, ...

Kaiser Wilhelm

Just now, I fixed the birth year and the 1921 stated age in the Wikipedia entry for baseballer Irvin K. Wilhelm — yet again! This time I added references.

Race Track

I transcribed an old Martin Gardner game today. It's called Race Track.

A076623 decomposed

I've been busy with a number of ongoing projects. I'm quite proud of my "number of left-truncatable primes by digit length" which I web-published yesterday and extended today. I still want to get actuals for bases 73, 32, 28, 79, 55, 83, 34, 89, 51, 65, 38, and (finally) 24, but it'll take a couple of months.

August 2011: They're all done! I've put a summary of bases tackled (with specifics) here.

Aliquot sequence 46758

I have gotten back to pursuing the fate of aliquot sequence 46758. On April 7, I found the 53-digit factor of term #3237, and early this morning, the 44-digit factor of term #3238. Terms 3239 (this used to be my Beer Store employee number) to 3249 proved relatively easy to factorize, so now I am working on the 113-digit composite of term #3250.

iMac interruptus

There was a power interruption this morning. This is the first time that my wife's iMac has rebooted since I started it running back in January. I make that to be 100 days.