A133477 is very nonidentical to same-titled A073185
N. J. A. Sloane
njas at research.att.com
Fri Nov 30 08:46:41 CET 2007
Thank you, Neil. You're right. In this case, "most people" are right.
1^3 = 1 is not cube-free. Okay.
It's a good thing that you corrected me before I submitted "Sum of
biquadrate-free divisors of n" or the array whose
2nd row is Sum of square-free divisors of n,
3rd row is Sum of cube-free divisors of n,
4th row is Sum of biquadrate-free divisors of n,
etecetera, perhaps read by antidiagonals, and with the main diagonal a
derived seq.
I may be a slow learner (and/or one of the "usual suspects") to only
after about 1800 tries have earned a "nice" -- but I have made some
cogent comments to 77 or so already "nice" seqs, in an effort to grok
niceness nicely.
Thank you again for being such a great teacher and editor and thinker,
-- Jonathan Vos Post
p.s. I've just been cleared to register for my 2nd quarter of grad
school in 34 years, this time towards my credentials to be a full-time
Math and Science teacher in California public high schools. Funny, the
hoops that I have to jump through, for 6/4 years of College of
Education to be "fully credentialed" as a high school Math teacher.
This is thanks to the unfunded Federal "No Child Left Behind" mandate,
which made almost all states add a layer of madness to their
bureaucracies, and annually dumb down their standardized tests to be
able to claim increasing scores [see the New York Times editorial of 2
days ago] and not be Federally penalized. Frankly, after teaching 5
semesters of Math as an Adjunct professor at one university [where
OEIS was a source of "extra credit" assignments], and Adjunct
Professor of Astronomy at another, and having over 2000 students in
other courses I've taught, and Algebra in a high school this summer,
one would think that I could enter a California classroom immediately.
But Law is a precedent-based logic, not axiom-based.
Joshua said:
No, one sequence is defined to exclude composite numbers, so it is
finite and ends with 97, while the other continues to include
composite numbers greater than 97.
I think it might be good practice -- but alternatively might be
against OEIS custom -- to add mention of things like that in the
cross-refs. Which do you recommend? Should A095862 say "Cf. A096489
is a version of this sequence that excludes composites" and A096489
composites" or something like that? Or is that kind of thing better
for the comments?
or %Y lines) is fine with me!
Neil
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