61–70 of 106 posts
...in decimal. https://t5k.org/notes/words.html points out that "When we work in base 36 all the letters are used - hence all words are numbers." Primes can be especially memorable in base 36. "Did," "nun," and "pop" are base-36 primes, as is "primetest" and many others.
My parents had had the number for two decades without noticing it was a palindrome. I still remember my father’s delight when he got off a phone call with a friend: “Doug just said, ‘Hey, I dialed your number backwards and it was still you who answered.’ I never noticed that before!”
A few years later, around 1973, one of the other math nerds at my high school liked to factor seven-digit phone numbers by hand just for fun. I was then taking a programming class—Fortran IV, punch cards—and one of my self-initiated projects was to write a prime factoring program. I got the program to work, and, inspired by my friend, I started factoring various phone numbers. Imagine my own delight when I learned that my home phone number was not only a palindrome but also prime.
Postscript: The reason we hadn’t noticed that 7984897 was a palindrome was because, until around 1970, phone numbers in our area were written and spoken with the telephone exchange name [1]. When I was small, I learned our phone number as “SYcamore 8 4 8 9 7” or “S Y 8 4 8 9 7.” We thought of the first two digits as letters, not as numbers.
Second postscript: I lost contact with that prime-factoring friend after high school. I see now that she went on to earn a Ph.D. in mathematics, specialized in number theory, and had an Erdős number of 1. In 1985, she published a paper titled “How Often Is the Number of Divisors of n a Divisor of n?” [2]. She died two years ago, at the age of sixty-six [3].
[1] https://en.wikipedia.org/wiki/Telephone_exchange_names
[2] https://www.sciencedirect.com/science/article/pii/0022314X85...
[3] https://www.legacy.com/us/obituaries/legacyremembers/claudia...
ChatGPT o1: https://chatgpt.com/share/678feedb-0b2c-8001-bd77-4e574502e4... > Thought about large prime check for 3m 52s: "Despite its interesting pattern of digits, 12,345,678,910,987,654,321 is definitely not prime. It is a large composite number with no small prime factors." Feels like this Online Encyclopedia of Integer Sequences (OEIS) would be a good candidate for a hallucination benchmark...
Can we stop with the "haha llms can't do math" nonsense? You'll one shot it every time if you tell it to use Python. You're holding it wrong.
https://en.wikipedia.org/wiki/Belphegor%27s_prime "666" with 13 0's on either side and 1's on the ends.
> Belphegor (or Baal Peor, Hebrew: בַּעַל-פְּעוֹר baʿal-pəʿōr – “Lord of the Gap”) is, in the Abrahamic religions, a demon associated with one of the seven deadly sins. According to religious tradition, he helps people make discoveries. He seduces people by proposing incredible inventions that will make them rich. Huh. Would feel right at home in our industry. > According to some demonologists from the 17th century,…
If you were around in the 80's and 90's you might have already memorized the prime 8675309 ( https://en.wikipedia.org/wiki/867-5309/Jenny ). It's also a twin prime, so you can add 2 to get another prime (8675311).
...in decimal. https://t5k.org/notes/words.html points out that "When we work in base 36 all the letters are used - hence all words are numbers." Primes can be especially memorable in base 36. "Did," "nun," and "pop" are base-36 primes, as is "primetest" and many others.
Why use base 36 and not base 26?
> Since prime numbers are very useful in secure communication, such easy-to-remember large prime numbers can be of great advantage in cryptography What's the use of notable prime numbers in cryptography? My understanding is that a lot of cryptography relies on secret prime numbers, so choosing a notable/memorable prime number is like choosing 1234 as your PIN. Are there places that need a prime that's arbitrary, larg…
> To use ECC, all parties must agree on all the elements defining the elliptic curve, that is, the domain parameters of the scheme. The size of the field used is typically either prime (and denoted as p) or is a power of two
like "25519"
> An EdDSA signature scheme is a choice: ... of finite field F q over odd prime power q ... Ed25519 is the EdDSA signature scheme where q = 2^255 - 19
[1] https://en.wikipedia.org/wiki/Elliptic-curve_cryptography#Do...
If you were around in the 80's and 90's you might have already memorized the prime 8675309 ( https://en.wikipedia.org/wiki/867-5309/Jenny ). It's also a twin prime, so you can add 2 to get another prime (8675311).
I was around in the 80s, but this is awesome new information!
My family’s phone number when I was a child was both a palindrome and a prime: 7984897. My parents had had the number for two decades without noticing it was a palindrome. I still remember my father’s delight when he got off a phone call with a friend: “Doug just said, ‘Hey, I dialed your number backwards and it was still you who answered.’ I never noticed that before!” A few years later, around 1973, one of the othe…
Claudia Spiro seems to have remained actively interested in prime numbers into her sixties. In 2017, she published a paper titled “On three consecutive prime-gaps”:
https://projecteuclid.org/journals/rocky-mountain-journal-of...