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URL: https://oeis.org/history?seq=A285738

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Showing entries 1-10 | older changes
Greatest prime less than 2*n^2 for n > 1, a(1) = 1.
#73 by Sean A. Irvine at Tue Jun 17 00:38:01 EDT 2025
STATUS
#72 by Stefano Spezia at Tue Jun 17 00:25:03 EDT 2025
STATUS
#71 by Jason Yuen at Tue Jun 17 00:20:52 EDT 2025
STATUS
#70 by Jason Yuen at Tue Jun 17 00:19:54 EDT 2025
MATHEMATICA
#69 by Jason Yuen at Tue Jun 17 00:18:12 EDT 2025
MATHEMATICA
STATUS
#68 by N. J. A. Sloane at Mon May 01 09:39:22 EDT 2017
STATUS
#67 by N. J. A. Sloane at Mon May 01 09:37:38 EDT 2017
COMMENTS
STATUS
Discussion
Mon May 01
09:39
N. J. A. Sloane: Deleted contentious claim about Legendre's conjecture.
#66 by N. J. A. Sloane at Sun Apr 30 22:47:58 EDT 2017
STATUS
#65 by Ralf Steiner at Thu Apr 27 06:54:31 EDT 2017
STATUS
Discussion
Thu Apr 27
07:10
Ralf Steiner: In my opinion there is a convention for the multiplication. Thus I don't think that a * is necessary there.
07:16
Ralf Steiner: well-ordered means as usually ..., 5,7,11,13, ...
07:29
Antti Karttunen: Ralf: Just edited https://oeis.org/draft/A285388 
Is it guaranteed that all of its terms are odd? (then my new "formula" (based on yours) should be valid, otherwise not).
07:31
Antti Karttunen: So "the upper part of at least n in i well-ordered prime factors p_i(n)" means at least n greatest prime factors (with or without multiplicity?) of n ?
07:40
Ralf Steiner: Antti: A285388 is approved.
07:50
Ralf Steiner: Antti: To your question. By my proof sketch YES. But Mathematica gives: OddQ[Numerator[2^(1 - 2 n^2) n Binomial[2 n^2, n^2]]]
=> FALSE 
==>> Note: Expressions that represent odd integers but do not evaluate explicitly will still give False.
08:17
Ralf Steiner: Antti: The at least n greatest prime factors are without multiplicity - these are single each.
16:19
David A. Corneth: I look forward to seeing the paper Ralf! If you need help, let me know.
16:28
Ralf Steiner: Thanks!
16:33
Ralf Steiner: David: I am still looking for the original paper of Legendre's Conjecture.
17:08
David A. Corneth: Okay, I'll help looking
17:51
David A. Corneth: Not found yet. In his list of publications there is one article I think might have it; "Essai sur la Théorie des Nombres", written by Legendre and published by Duprat in 1798. I can't find it online but it is said to be in a library near me.
17:57
David A. Corneth: Here's a scanned version: http://www.biodiversitylibrary.org/item/58163#page/6/mode/1up
Fri Apr 28
00:43
Ralf Steiner: Great - thank you!
01:32
Antti Karttunen: Dear Dr. Steiner, Could I replace your sentence in the beginning of https://oeis.org/draft/A285388 "a(n) has at least n prime factors, each A285738(n) less than 2*n^2" WITH THIS "a(n) has at least n prime factors, the largest of them which is A285738(n), which is the greatest prime less than 2*n^2" ? Or is there more contents into it?
01:34
Antti Karttunen: Please see also my new formula in https://oeis.org/draft/A285406
Fundamentally, it is based on Vladimir Shevelev's Jul 20 2009 formula in A000984, that A007814(A000984(n)) = A000120(n).
02:10
Ralf Steiner: Antti: replaced
02:31
Ralf Steiner: David: The book has 562 pages. Do you know where the essential sentences for his conjecture are written?
02:34
Antti Karttunen: @02:10. Ralf: Thanks!
02:41
Ralf Steiner: I don't find (using search function) a term like (n+1) in his book.
02:45
Ralf Steiner: Maybe his conjecture is "between the lines", but where?
02:59
Ralf Steiner: Antti, David: Please visit my latest note at A285786 with a question regarding the original conjecture.
06:21
Ralf Steiner: After studying Legendre's book from 1797 a bit I am sure that the interval (2(n-1)^2, n^2 ) used in my proof also fullfil his conjecture.
07:15
Ralf Steiner: I propose the sequence is ready now to become the status "approved".
#64 by Ralf Steiner at Thu Apr 27 06:47:58 EDT 2017
CROSSREFS
STATUS
Discussion
Thu Apr 27
06:52
Ralf Steiner: The A285786 is referred to now - sorry for the space. Please note that A285786 and A014085 are interleaved with sqrt(2).
06:56
Antti Karttunen: Also, maybe an example what are "i well-ordered prime factors p_i(n)" ? (I guess your paper will shed more light on this.)