Forum: Puzzles
2020-10-31, 07:12
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Replies: 1
Views: 538
This one isn't in the OEIS
Hello,
New puzzle that I thought up :
What sequence's representation starts with 5, 16, 361.
It's not in the online encyclopedic integer sequences, so you will...
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Forum: Number Theory Discussion Group
2020-10-27, 19:44
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Replies: 27
Views: 2,102
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Forum: Number Theory Discussion Group
2020-10-27, 06:44
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Replies: 27
Views: 2,102
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Forum: Number Theory Discussion Group
2020-10-26, 17:07
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Replies: 27
Views: 2,102
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Forum: Lounge
2020-10-24, 18:57
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Replies: 0
Views: 318
Prime time
Remember tonight to go from π(τ) to π(π) :):smile:
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Forum: Number Theory Discussion Group
2020-10-23, 19:20
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Replies: 27
Views: 2,102
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Forum: Number Theory Discussion Group
2020-10-23, 18:12
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Replies: 27
Views: 2,102
Co prime doesn't mean prime, and I still don't...
Co prime doesn't mean prime, and I still don't understand why the odds are to think that the conjecture is wrong, okay, it's incompatible with the first, but there is no particular reason to think...
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Forum: Number Theory Discussion Group
2020-10-23, 14:11
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Replies: 27
Views: 2,102
Answer
Simply because in any sequence 53#*n to 53#*n+1, all the numbers that are congruent to x*{2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53} modulo 53# will be divisible by a prime up to 53....
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Forum: Lounge
2020-10-23, 13:53
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Replies: 44
Views: 6,031
Efficient bases for finding primes
I noticed that if we classify the bases according to how efficient they are to identify at once (by the last digit) composites, base 10 is "quite" good, but not the best!
Not even up to 10, as base...
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Forum: Number Theory Discussion Group
2020-10-23, 08:11
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Replies: 27
Views: 2,102
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Forum: Number Theory Discussion Group
2020-10-22, 16:35
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Replies: 27
Views: 2,102
But the region where they are searching is over...
But the region where they are searching is over 10^174, so, if we want to find within a sequence of 3159, 447 prime numbers, that means that the interval, this high, must contain even less composite...
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Forum: Number Theory Discussion Group
2020-10-22, 14:07
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Replies: 27
Views: 2,102
2nd Hardy-Littlewood conjecture
Hello,
I've looked at the way primes behave in sequences which have a primorial length and, as I mentionned a few weeks ago, I came across the 2nd Hardy-Littlewood conjecture, which was...
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Forum: Lounge
2020-10-17, 17:24
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Replies: 447
Views: 22,339
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Forum: Lounge
2020-10-17, 12:12
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Replies: 447
Views: 22,339
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Forum: Puzzles
2020-10-16, 05:10
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Replies: 32
Views: 2,164
1, 3
I would guess the triangular numbers, at least, it's a possibility.
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Forum: Hobbies
2020-10-13, 13:55
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Replies: 1
Views: 805
Languages
Hello
I suggest, since we're in the hobby part, this thread to discuss the languages that we know about and maybe learn from eachother.
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Forum: Lounge
2020-10-13, 12:44
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Replies: 447
Views: 22,339
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Forum: Puzzles
2020-10-12, 15:29
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Replies: 32
Views: 2,164
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Forum: Puzzles
2020-10-12, 15:13
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Replies: 32
Views: 2,164
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Forum: Puzzles
2020-10-12, 15:02
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Replies: 32
Views: 2,164
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Forum: Puzzles
2020-10-12, 15:00
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Replies: 32
Views: 2,164
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Forum: Puzzles
2020-10-12, 14:58
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Replies: 32
Views: 2,164
OEIS
I don't know about the last one but fore base 30, I checked and it seems that OEIS is right, it's not prime.
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Forum: Puzzles
2020-10-12, 14:39
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Replies: 32
Views: 2,164
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Forum: Lounge
2020-10-12, 11:47
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Replies: 447
Views: 22,339
oops
I forgot to post the next number :
30 031
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Forum: Lounge
2020-10-12, 10:53
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Replies: 447
Views: 22,339
Good
Yes, that's right!
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