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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.

ABC

Three 3-digit numbers, a, b, and c, have no digits in common and a^b ± c are both prime.

Birdo

444085 Ruth-Aaron pairs

I contacted Donovan Johnson and he was kind enough to share his list of Ruth-Aaron numbers less than 10^12. So I added the additional terms to my compilation: 444085 factored pairs @ 66.5 MB.

150000 Ruth-Aaron pairs

I am done with my Ruth-Aaron pairs compilation for now. I finished around 3:30 a.m. this morning: 150000 factored pairs @ 22.5 MB. I discovered that the number of terms less than 10^11 was not 106770 as indicated here, but 106670 as indicated here (I had not been aware of this sequence before today). I also now know that the Herman Baer Ruth-Aaron number 174024968568 sits at index 149492. Mr. Baer estimates here that its index is ~2050, but reduces that guess to ~1123 just a few weeks later.