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Revision History for A224363 (Bold, blue-underlined text is an addition; faded, red-underlined text is a deletion.)

Showing entries 1-10 | older changes
Primes p such that there are no squares between p and the prime following p.
(history; published version)
#13 by Reinhard Zumkeller at Mon Apr 15 10:07:35 EDT 2013
STATUS

editing

approved

#12 by Reinhard Zumkeller at Mon Apr 15 09:51:45 EDT 2013
COMMENTS

a(n) = A000040(A221056(n)). - Reinhard Zumkeller, Apr 15 2013

LINKS

Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/LegendresConjecture.html">Legendre's Conjecture</a>

Wikipedia, <a href="http://en.wikipedia.org/wiki/Legendre%27s_conjecture">Legendre's conjecture</a>

PROG

(Haskell)

a224363 = a000040 . a221056 -- Reinhard Zumkeller, Apr 15 2013

CROSSREFS
#11 by Reinhard Zumkeller at Mon Apr 15 09:50:10 EDT 2013
LINKS

Reinhard Zumkeller, <a href="/A224363/b224363.txt">Table of n, a(n) for n = 1..10000</a>

STATUS

approved

editing

#10 by T. D. Noe at Fri Apr 12 13:20:13 EDT 2013
STATUS

editing

approved

#9 by T. D. Noe at Fri Apr 12 13:20:02 EDT 2013
DATA

2, 5, 11, 17, 19, 29, 37, 41, 43, 53, 59, 67, 71, 73, 83, 89, 101, 103, 107, 109, 127, 131, 137, 149, 151, 157, 163, 173, 179, 181, 191, 197, 199, 211, 227, 229, 233, 239, 241, 257, 263, 269, 271, 277, 281, 293, 307, 311, 313, 331, 337, 347, 349, 353, 367, 373

MATHEMATICA

Select[Prime@[Range@[60, ]], Floor@[Sqrt@[NextPrime@[# ]]] == Floor@[Sqrt@[# ]] &] (* Giovanni Resta, Apr 10 2013 *)

STATUS

reviewed

editing

#8 by Michael B. Porter at Thu Apr 11 23:39:39 EDT 2013
STATUS

proposed

reviewed

Discussion
Fri Apr 12
03:19
Giovanni Resta: I can't help. I'm a researcher in computer science, not a professional mathematician nor a genius. This conjecture is probably as difficult as the last Fermat theorem, so thinking that an amateur like me can find a proof, while a multitude of very skilled geniuses in mathematics have failed, is childish at best. I like to waste my time on more promising ventures... but good luck!
#7 by Giovanni Resta at Wed Apr 10 19:21:03 EDT 2013
STATUS

editing

proposed

Discussion
Thu Apr 11
16:37
César Aguilera: Thank you Resta. These comments are not the proof, of course. I'm working on it (if someone wants to help me, is welcome). At least T.D don't say that this is unacceptable.
#6 by Giovanni Resta at Wed Apr 10 19:12:32 EDT 2013
NAME

Consecutive primes with Primes p such that there are no square squares between themp and the prime following p.

DATA

2, 5, 11, 17, 19, 29, 37, 41, 43, 53, 59, 67, 71, 73, 83, 89, 101, 103, 107, 109, 113, 127, 131, 137, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 227, 229, 233, 239, 241, 257, 263, 269, 271, 277, 281

COMMENTS

On The Legendré Legendre's Conjecture states that there is a prime between n^2 and (n+1)^2 for every integer n > 0 and thus that between two adjacent primes there can be at most one square. As of April 2013, the conjecture is still unproved.

Every square is between primes.

For n≤2, there is always a prime such that:

p< n^2 <p

and

p< (n+1)^2 <p

so

n^2<p<(n+1)^2<p

if

p<n^2=p<(n+1)^2 then p is between [n^2,(n+1)^2]

p<n^2≠p<(n+1)^2 then p is between [n^2, (n+1)^2]

if

p<n^2<(n+1)^2 and p>(n+1)^2>n^2

So we need that 'prime factors' (fp)

fp<n^2<(n+1)^2 and fp>(n+1)^2>n^2

then we have:

n+n^2+(n+1)=(n+1)^2

n+n^2<(n+1)^2

n+(n+1)<(n+1)^2

2n+1<(n+1)^2

then:

(fp)^2>(n+1)^2 (is not true)

so

knowing that for n≥3 there are no primes of the form n^2-1 and n^2 can not be a prime

The Legendré Conjecture is true for [(n^2+1),(n+1)^2-2]

EXAMPLE

5, is a term because there is are no square squares between the adjacent primes 5 and 7 or.

n^2< {5,7} < (n+1)^2 for n=2

MATHEMATICA

Select[Prime@Range@60, Floor@Sqrt@NextPrime@# == Floor@Sqrt@# &] (* Giovanni Resta, Apr 10 2013 *)

EXTENSIONS

Corrected and edited by Giovanni Resta, Apr 10 2013

STATUS

proposed

editing

Discussion
Wed Apr 10
19:20
Giovanni Resta: Dear Cesar, I had to delete a large part of your comment because it was a mess. Reading it, it seemed you did think to have found a prove of Legendre's Conjecture, which is clearly not the case. Please note that mathematics has its own language which cannot be used in that way. For example, you cannot write "For n<=2, there is always a prime such that: p< n^2 <p  ", because you cannot use the letter p for two different primes in the same formula.
#5 by César Aguilera at Wed Apr 10 18:16:58 EDT 2013
STATUS

editing

proposed

#4 by César Aguilera at Wed Apr 10 18:16:38 EDT 2013
EXAMPLE

n^2< {5,7} < (n+1)^2 for n=2