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Search: Posts Made By: enzocreti
Forum: enzocreti 2022-03-06, 12:54
Replies: 14
Views: 11,669
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: 11,669
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: 11,669
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: 11,669
Posted By enzocreti
...

the last you said
Forum: enzocreti 2021-07-11, 10:02
Replies: 14
Views: 11,669
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: 3,269
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: 2,261
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: 1,741
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: 1,951
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: 3,734
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: 6,141
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: 6,141
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: 6,141
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: 6,141
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: 6,141
Posted By enzocreti
Unfortunally my computer is broken!

Unfortunally my computer is broken!
Forum: enzocreti 2020-08-31, 11:27
Replies: 20
Views: 6,141
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: 7,096
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: 7,096
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: 7,096
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...
Forum: enzocreti 2020-08-28, 14:46
Replies: 11
Views: 7,096
Posted By enzocreti
numbers of yet another particular type

Consider numbers N squarefree that is in the factorisation of N there is no prime facor raised to a power greater than 1.




56238 is square free


56238 has five digits
Forum: enzocreti 2020-08-27, 07:50
Replies: 0
Views: 2,415
Posted By enzocreti
ec exponents in position 9n

a(9)=36
a(18)=1323
a(27)=69660
a(36)=360787



pg(36), pg(1323) and pg(69660) and pg(360787) are primes
Forum: enzocreti 2020-08-19, 05:48
Replies: 14
Views: 11,669
Posted By enzocreti
Q77I 215 69660 92020 541456 are...

Q77I


215 69660 92020 541456 are congruent to plus or minus (6^k-1) mod 323 for k=3,2


69660=(2^5*3^7)-(2^3*3^4) so it is the difference of two 3 smooth numbers (2^a*3^b)-(2^(a-3)*3^(b-3))
Forum: enzocreti 2020-07-23, 07:33
Replies: 0
Views: 3,099
Posted By enzocreti
pg(308899)

pg(69660) is prime
pg(92020) is prime and 92020+239239 is prime
pg(92020+239239) is prime




Now i consider
Forum: enzocreti 2020-07-02, 09:29
Replies: 0
Views: 2,680
Posted By enzocreti
collatz 3x+1

I found a forumula about the 3x+1 problem


let be T(k,n) the trajectory starting from integer n.


k is the number of iterations


T(0,n)=n i think
Forum: enzocreti 2020-06-21, 22:01
Replies: 4
Views: 3,640
Posted By enzocreti
Pg(69660) pg(92020) and pg(541456) pg(k) primes with k multiple of 86

This identity involves pg(k) primes with k multiple of 86

k multiple of 86 with pg(k) primes satisfy this identity

541456-(69660*16/10+1000)=1000*sqrt(92020*2+1)


pg(366770) is prime and...
Showing results 1 to 25 of 532

 
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