[seqfan] Re: Announcements: faster search, new Sys Admin

David Seal david.j.seal at gwynmop.com
Wed Jun 26 17:18:52 CEST 2019

> On 23 June 2019 at 22:19 Russ Cox <rsc at swtch.com> wrote:
> ...
> The hints page https://oeis.org/hints.html is updated with the new
> state of the world.

A 'matter arising' comment triggered by this: the statement on that page that "◾Strings of words should be separated by spaces (NOT commas)" seems a bit too strong to me - shouldn't it be something like "◾Strings of words should normally be separated by spaces. Separate them with commas only if you want those words in that order, with no other words between them."?

I ask because this thread and looking at the new hints page has just caused me to realise that searching for a string of words separated by commas is a good-enough solution to an issue I had a while back (but never got around to posting about). The issue was that I was interested in sequences relating to powerful numbers, but a search for "powerful" also matches sequences that contain the related words "power" and "powers". Those words are of course very common, so searching for them currently produces 16503 results - far too many to trawl through for the sequences I was interested in. I tried searching for "powerful number" to narrow it down, but "number" is of course also a very common word, and that search still produces 8704 results.

But searching for "powerful,number" narrows it down a lot more, to 184 results. They still contain quite a few sequences with passages like "Prime powers: numbers of the form p^k where p is a prime and k >= 1.", so an ability to search for an exact word with no substitutes allowed would be a better solution, but picking out the results I was interested in is now a manageable task.


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