Block #308,323

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/13/2013, 1:28:01 AM · Difficulty 9.9945 · 6,496,462 confirmations

1CC
Cunningham Chain of the First Kind

A sequence where each prime is double the previous prime plus one.

Block Header
Block Hash
52c7cc72100bdd340dbb4f3ac96309b85e8b059959a508000922a9c521a7bc06

Height

#308,323

Difficulty

9.994454

Transactions

19

Size

7.63 KB

Version

2

Bits

09fe9483

Nonce

217,620

Timestamp

12/13/2013, 1:28:01 AM

Confirmations

6,496,462

Merkle Root

c28c961f4954f790e29344f4848a1eb8263534d3e6220a4e5cb75e97b036f778
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) — it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

1.035 × 10¹⁰¹(102-digit number)
10359295079125886057…17653257767944564399
Discovered Prime Numbers
p_k = 2^k × origin − 1

These are the actual prime numbers discovered by this block, computed using the verified Primecoin formula. Each number has been independently confirmed to pass the Fermat primality test. Use the FactorDB links to verify any number independently.

1
origin − 1
1.035 × 10¹⁰¹(102-digit number)
10359295079125886057…17653257767944564399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.071 × 10¹⁰¹(102-digit number)
20718590158251772115…35306515535889128799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.143 × 10¹⁰¹(102-digit number)
41437180316503544231…70613031071778257599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.287 × 10¹⁰¹(102-digit number)
82874360633007088463…41226062143556515199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.657 × 10¹⁰²(103-digit number)
16574872126601417692…82452124287113030399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.314 × 10¹⁰²(103-digit number)
33149744253202835385…64904248574226060799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.629 × 10¹⁰²(103-digit number)
66299488506405670770…29808497148452121599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.325 × 10¹⁰³(104-digit number)
13259897701281134154…59616994296904243199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.651 × 10¹⁰³(104-digit number)
26519795402562268308…19233988593808486399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
5.303 × 10¹⁰³(104-digit number)
53039590805124536616…38467977187616972799
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 10 consecutive prime numbers forming a Cunningham Chain of the First Kind. The prime chain origin — the large number shown above — anchors the chain and is divisible by a primorial (the product of small primes), cryptographically tying these prime numbers to this specific block.

★★☆☆☆
Rarity
UncommonChain length 10

Roughly 1 in 100 blocks. Solid but expected in a healthy network.

How Primecoin's Proof-of-Work Constructs These Primes

Primecoin stores a value called the prime chain origin in each block. The miner found a large integer such that when divided by a primorial (the product of small primes: 2 × 3 × 5 × 7 × …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial — that divisibility is part of the proof.

Prime Chain Origin = First Prime × Primorial (2·3·5·7·11·…)
Source: Primecoin prime.cpp — CheckPrimeProofOfWork()

This is why the origin has many small prime factors — those factors are the primorial divisor. The chain then extends from the first prime using the 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,682,344 XPM·at block #6,804,784 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.