A Number Of Numbers
Back in my math major days in college, I was introduced to the Online Journal of Integer Sequences. It’s exactly what it says on the tin. As part of a class we were encouraged to contribute, which I did.
A few weeks ago I had another idea for a submission, and to my surprise no one else had added it, so once again I had opportunity to contribute a little piece of Internet history.
Here’s a complete list of the sequences I’ve authored over the years:
- Sum of the divisors of the sum of the divisors of n
- Primes in the Jacobsthal sequence
- a(1) = 5, a(n) = sigma(a(n-1)) (probably needs a fancier name)
- Chernoff sequence divided by 2
- Number of ordered ways of writing n as a sum of 5 generalized pentagonal numbers (this was my senior capstone project in college)
- Numbers whose digits have a permutation that is a palindrome
- Product of n and its binary ones’ complement (my most recent one)
If the above isn’t enough online notoriety, check out my only published mathematical work, A Probabilistic View of Certain Weighted Fibonacci Sums. I was only a mild contributor, but still got an authorial credit, which is pretty cool.