Mathematical Meanderings

I'm surprised I've not come across this type of sequence before. It has two variants and they are generated iteratively as follows: ...

 FIRST EXAMPLE The numbers 1 and 4 have the interesting properties that: their sum is prime: 1 + 4 = 5 their difference is prime: 4 - 1 = 3 ...

Yesterday I turned 27487 days old. This is a prime number of days and this number together with the next three prime numbers form the follow...

On January 1st 2024, I made a post titled Unitary Harmonic Numbers  which are defined as numbers whose unitary divisors have a harmonic mean...

Every fourth number is a multiple of 4 and so there cannot be a run of four consecutive numbers that are the product of two distinct primes....