 mersenneforum.org > Math Carmichael numbers and Šimerka numbers
 Register FAQ Search Today's Posts Mark Forums Read  2018-10-30, 12:08 #1 devarajkandadai   May 2004 1001111002 Posts Carmichael numbers and Šimerka numbers As you are aware Carmichael numbers pertain to the property of composite numbers behaving like prime numbers with regard to Fermat's theorem. They are Devaraj numbers I.e. if N = p_1*p_2....p_r ( where p_i is prime) then (P_1-1)*(N-1)/(p_2-1)......... (p_r-1) is an integer. See A104016 and A104017. a) conjecture: the least value of k, the degree to which atleast two of a Devaraj number's prime factors are Inverses, is 2 (example 561 = 3*11*17 -here 3 and 17 are inverses (mod 5^2). b) 5 and 11 are impossible cofactors of Devaraj numbers (including Carmichael numbers). (to be continued)   2018-10-30, 14:18   #2

May 2004

22×79 Posts Carmichael numbers and Devaraj numbers

Quote:
 Originally Posted by devarajkandadai As you are aware Carmichael numbers pertain to the property of composite numbers behaving like prime numbers with regard to Fermat's theorem. They are Devaraj numbers I.e. if N = p_1*p_2....p_r ( where p_i is prime) then (P_1-1)*(N-1)^(r-2)*(p_2-1)......... (p_r-1) is an integer. See A104016 and A104017. a) conjecture: the least value of k, the degree to which atleast two of a Devaraj number's prime factors are Inverses, is 2 (example 561 = 3*11*17 -here 3 and 17 are inverses (mod 5^2). b) 5 and 11 are impossible cofactors of Devaraj numbers (including Carmichael numbers). (to be continued)
C) 7 and 31 are inverses of 3rd degree

Last fiddled with by devarajkandadai on 2018-10-30 at 14:19 Reason: Corrected a slip   2018-10-30, 14:24   #3

May 2004

1001111002 Posts Carmichael numbers and Devaraj numbers

Quote:
 Originally Posted by devarajkandadai As you are aware Carmichael numbers pertain to the property of composite numbers behaving like prime numbers with regard to Fermat's theorem. They are Devaraj numbers I.e. if N = p_1*p_2....p_r ( where p_i is prime) then (P_1-1)*(N-1)^(r-2)*(p_2-1)......... (p_r-1) is an integer. See A104016 and A104017. a) conjecture: the least value of k, the degree to which atleast two of a Devaraj number's prime factors are Inverses, is 2 (example 561 = 3*11*17 -here 3 and 17 are inverses (mod 5^2). b) 5 and 11 are impossible cofactors of Devaraj numbers (including Carmichael numbers). (to be continued)
C) 7 and 31 are inverses of 3rd degree since 7 and 31 are inverses (mod 3^3).   2018-11-02, 05:54   #4

May 2004

13C16 Posts Carmichael numbers and Devaraj numbers

Quote:
 Originally Posted by devarajkandadai C) 7 and 31 are inverses of 3rd degree since 7 and 31 are inverses (mod 3^3).
Carmichael numbers are subset of Devaraj numbers
Devaraj numbers subset of tortionfree numbers of degree k.   2018-11-04, 05:30   #5

May 2004

22×79 Posts Carmichael numbers and Devaraj numbers

Quote:
 Originally Posted by devarajkandadai Carmichael numbers are subset of Devaraj numbers Devaraj numbers subset of tortionfree numbers of degree k.
41and 61 are inverses of degree 4 (mod 5^4).
17 and 6947 are inverses of degree 10 (mod 3^10).   2018-11-05, 04:16   #6

May 2004

4748 Posts Quote:
 Originally Posted by devarajkandadai 41and 61 are inverses of degree 4 (mod 5^4). 17 and 6947 are inverses of degree 10 (mod 3^10).
175129 and 3403470857219 are inverses of degree 25 (mod 5^25)   2018-11-05, 06:05 #7 Batalov   "Serge" Mar 2008 Phi(4,2^7658614+1)/2 2·11·457 Posts Well, 5 and 7469128023...77<181> are goddamn inverses of degree 600. 131 and 1289338297...07<1808> are inverses of degree 6002. 3 and (4025*2^66666+1)/3 are inverses of degree 66666. 7 and (3*2^320008+1)/7 are inverses of degree 320008. There are thousands of similar anecdotal cases. Do you have a point to make other than torture random semiprime numbers?   2018-12-01, 06:44   #8

May 2004

13C16 Posts Quote:
 Originally Posted by devarajkandadai As you are aware Carmichael numbers pertain to the property of composite numbers behaving like prime numbers with regard to Fermat's theorem. They are Devaraj numbers I.e. if N = p_1*p_2....p_r ( where p_i is prime) then (P_1-1)*(N-1)/(p_2-1)......... (p_r-1) is an integer. See A104016 and A104017. a) conjecture: the least value of k, the degree to which atleast two of a Devaraj number's prime factors are Inverses, is 2 (example 561 = 3*11*17 -here 3 and 17 are inverses (mod 5^2). b) 5 and 11 are impossible cofactors of Devaraj numbers (including Carmichael numbers). (to be continued)
C) let N = (2*m+1)*(10*m+1)*(16*m+1)- here m is a natural nnumber. Then N is a Carmichael number if a) for a given value of m, 2*m+1, 10*m+1 and 16*m+1 are prime and b) 80*m^2 + 53*m + 7 is exactly divisible by 20.   2018-12-01, 16:43   #9
Batalov

"Serge"
Mar 2008
Phi(4,2^7658614+1)/2

2·11·457 Posts Quote:
 Originally Posted by devarajkandadai ... and b) 80*m^2 + 53*m + 7 is exactly divisible by 20.
This simply means that m=20*q+1. And therefore what you are trying to say looks like a Chernick-like recipe for 3-prime factor Carmichael numbers: "if 40*q + 3, 200*q + 11 and 320*q + 17 are all prime, then their product is a Carmichael number".

With a difference that Chernick proved his and you are "just saying". To what limit did you even test it?   2018-12-01, 17:25   #10
science_man_88

"Forget I exist"
Jul 2009
Dartmouth NS

100000111000102 Posts Quote:
 Originally Posted by Batalov And therefore what you are trying to say looks like a Chernick-like recipe for 3-prime factor Carmichael numbers: "if 40*q + 3, 200*q + 11 and 320*q + 17 are all prime, then their product is a Carmichael number".
which only works if q is 1 mod 3, because the first defeats 0 mod 3 and the others fail for 2 mod 3.   2018-12-01, 20:59   #11
Batalov

"Serge"
Mar 2008
Phi(4,2^7658614+1)/2

274616 Posts Quote:
 Originally Posted by science_man_88 which only works if q is 1 mod 3, because the first defeats 0 mod 3 and the others fail for 2 mod 3.
...except q=0 (because 3 is allowed to be divisible by 3 and still be prime)   Thread Tools Show Printable Version Email this Page Similar Threads Thread Thread Starter Forum Replies Last Post devarajkandadai Number Theory Discussion Group 1 2018-07-30 03:44 devarajkandadai Number Theory Discussion Group 14 2017-11-15 15:00 devarajkandadai Number Theory Discussion Group 0 2017-07-09 05:07 Stan Miscellaneous Math 19 2014-01-02 21:43 devarajkandadai Math 0 2004-08-19 03:12

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