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Forum: enzocreti 2022-09-23, 10:10
Replies: 2
Views: 113
Posted By enzocreti
1666667*2 mod 666667

how do you see that

-1666667x2=1 mod 666667?

I simply tried but is there a method to "see" it?
Forum: enzocreti 2022-09-21, 07:35
Replies: 5
Views: 251
Posted By enzocreti
odd

but 13 is odd
Forum: enzocreti 2022-09-19, 09:28
Replies: 5
Views: 251
Posted By enzocreti
numbers of the form 24n+2

Is it correct that every number of the form 24n+2 cannot be of the form 3m+1? for m,n positive integers?


mod 3 this should yeld to 2=1 mod 3?


using chinese remainder theorem

only numbers...
Forum: enzocreti 2022-09-14, 18:21
Replies: 1
Views: 268
Posted By enzocreti
How to prove that only Powers of 6^(6+35j) are of the form648+23004s

This Is a Little more difficult:

How to prove that Powers 6^(6+35j) for j nonnegative integer are of the form 648+23004s and only that powers .

I mean there Is no orher 6^g of the form...
Forum: enzocreti 2022-09-13, 09:30
Replies: 4
Views: 218
Posted By enzocreti
the congruence should be equal to 6^6=0 mod...

the congruence should be equal to

6^6=0 mod 4

6^6=0 mod 81

6^6=9 mod 71

so the least exponent k for which 6^k=1 is k=35 a divisor of (71-1)=0
Forum: enzocreti 2022-09-13, 07:22
Replies: 4
Views: 218
Posted By enzocreti
Proving every 6^(6+35j)=648 mod 23004

How to prove that every 6^(6+35j) for nonnegative j is congruent to 648 mod 23004?

By Fermat litle theorem I can say (71-1)=70, 35 divides 70, so 6^35=1 mod 71

But how to continue the proof?
Forum: enzocreti 2022-03-06, 12:54
Replies: 14
Views: 12,783
Posted By enzocreti
3067 is a prime there is a very complex...

3067 is a prime

there is a very complex hidden structure

331259/3680 is very close to 90

7775*23005+1 Is a Square

-331259=3067-1 mod 7775
Forum: enzocreti 2022-01-03, 13:06
Replies: 14
Views: 12,783
Posted By enzocreti
92233=427x6^3+1 92233=6^3=51456 mod 427 ...

92233=427x6^3+1

92233=6^3=51456 mod 427

((92233-51456)-1)/3-12592=10^3
Forum: enzocreti 2021-07-11, 20:35
Replies: 14
Views: 12,783
Posted By enzocreti
215*107*12^2 is congruent to -71*6^6 which is...

215*107*12^2 is congruent to -71*6^6 which is congruent to 72 mod (331*139)


331*139*8 is congruent to -8 mod (215*107)


s^2 is congruent to 1 mod 23005

the first not trivial solution is
Forum: enzocreti 2021-07-11, 19:07
Replies: 14
Views: 12,783
Posted By enzocreti
...

the last you said
Forum: enzocreti 2021-07-11, 10:02
Replies: 14
Views: 12,783
Posted By enzocreti
Now i consider 215*107*x is congruent to 1...

Now i consider

215*107*x is congruent to 1 mod (331*139)

the solution is x=2+46009*s, for some s

when s=8

(215*107*(2+46009*8)-1)/(331*139)=429^2=2*92020+1
Forum: enzocreti 2020-10-27, 13:01
Replies: 10
Views: 3,524
Posted By enzocreti
a difficult problem

Let be N a nonnegative integer.


I search integers N such that


N+20=s^2*p and N+19=q^2*(2*p+1), where s and q are integers>1 and p is a prime>2 and (2p+1) is a prime as well.
Forum: enzocreti 2020-09-30, 13:44
Replies: 2
Views: 2,490
Posted By enzocreti
How to proof that numbers 18, 108, 1008,...will never be divisible by 6^4?

How to proof that numbers of the form 18, 108, 1008, 10008, 100008, 1000...0008 will never be divisible by 6^4?
Forum: enzocreti 2020-09-29, 14:46
Replies: 1
Views: 1,944
Posted By enzocreti
Is 56238 the only N with this property?

Is 56238 the only positive integer N such that


sigma(N)/546=2^j, where j is a positive integer?


sigma is the sum of the divisors of N
Forum: enzocreti 2020-09-29, 09:26
Replies: 3
Views: 2,175
Posted By enzocreti
sigma(n)=x*(x+1)^3

let be sigma(n) the sum of the divisors of n




something is known about numbers n such that


sigma(n)=x*(x+1)^3 with x positive integer?
Forum: enzocreti 2020-09-01, 08:43
Replies: 3
Views: 3,917
Posted By enzocreti
...factorial(n) plus/minus 1 is semiprime

Is there an Oeis sequence dedicated to numbers n such that n!+1 and n!-1 are both semiprime? An example is 20970


Infact 20970!+1 is semiprime and also 20970!-1 is semi prime




No the...
Forum: enzocreti 2020-09-01, 07:53
Replies: 20
Views: 6,592
Posted By enzocreti
...i did not...

i did not take into account that N must be 10^m mod 41




let's guess congruent to 1 mod 41
Forum: enzocreti 2020-09-01, 07:32
Replies: 20
Views: 6,592
Posted By enzocreti
...not that's not prp

how about this:


(2^1430136-1)*10^430514+2^1430135-1???


I made a stupid mistacke


the candidates have the form
Forum: enzocreti 2020-09-01, 07:21
Replies: 20
Views: 6,592
Posted By enzocreti
...but this is almost surely PRP!

(2^3680800-1)*10^1108031+2^3680799-1
Forum: enzocreti 2020-08-31, 15:43
Replies: 20
Views: 6,592
Posted By enzocreti
Pg(69660) is prime 69660 is multiple of...

Pg(69660) is prime


69660 is multiple of 215 and congruent to 215 mod 323...it is also 6 mod 13... using wolphram numbers of this form are 69660+xn where x i don't remember what it is.

69660...
Forum: enzocreti 2020-08-31, 13:52
Replies: 20
Views: 6,592
Posted By enzocreti
Unfortunally my computer is broken!

Unfortunally my computer is broken!
Forum: enzocreti 2020-08-31, 11:27
Replies: 20
Views: 6,592
Posted By enzocreti
probable dud

((2^1875230-1)*10^564501+2^1875229-1) has small factors?


I don't know...:smile:
Forum: enzocreti 2020-08-29, 08:01
Replies: 11
Views: 7,471
Posted By enzocreti
... 56238...

56238 is a not palindromic number such that the reverse 83265 (squarefree) also belongs to Oeis sequence A165256. Are there other examples of not palindromic numbers belonging to A165256 whose...
Forum: enzocreti 2020-08-28, 18:02
Replies: 11
Views: 7,471
Posted By enzocreti
Are 56238 and 75894 the only multiple of 546...

Are 56238 and 75894 the only multiple of 546 squarefree belonging to the sequence A165256 ?
Forum: enzocreti 2020-08-28, 16:42
Replies: 11
Views: 7,471
Posted By enzocreti
... 75894...

Pg(56238) is prime and also pg(75894) is prime

56238 and 75894 are multiple of 546.

56238 and 75894 are square free and belong to the Oeis sequence you mentioned


Pg(n) is the concatenation...
Showing results 1 to 25 of 538

 
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