XPM Prime Explorer
Every Primecoin block mined discovers a new prime number chain. Track them all in real time.
Recent Blocks
Latest blocks from the Primecoin network
Learn About Prime Numbers
Explore the mathematics, cryptography, and history behind Primecoin's proof-of-work algorithm. From safe primes to Cunningham chains, discover why prime number discovery matters.
What is a Prime Chain?
Primecoin's proof-of-work algorithm searches for three specific types of prime number chains. Each mined block must contain a valid chain, making the work mathematically meaningful.
Cunningham Chain 1st Kind
A sequence of primes where each term is double the previous plus one. Named after mathematician Allan Cunningham.
Cunningham Chain 2nd Kind
A sequence of primes where each term is double the previous minus one. The mirror counterpart of the 1st kind.
Bi-Twin Chain
Two interleaved Cunningham chains sharing the same origin, producing twin prime pairs at each step.
Chain Length Distribution
How often each chain length appears in the Primecoin blockchain, computed from real synced data.
Based on 260,509 synced blocks