Block #322,828

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 12/21/2013, 6:56:20 AM · Difficulty 10.1921 · 6,483,278 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
45d2c699c0f26d2916be991e4fa317a5f8e71a0817948490cd4e2bffe2d85c4f

Height

#322,828

Difficulty

10.192076

Transactions

10

Size

3.91 KB

Version

2

Bits

0a312be7

Nonce

3,954

Timestamp

12/21/2013, 6:56:20 AM

Confirmations

6,483,278

Merkle Root

21620f9d4c24d0e51e7f233dc20f532f69d6cbf53ade3ebf05d2c16f7e3989b6
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.

3.126 × 10⁹⁸(99-digit number)
31262249294543294349…42092246736747391999
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
3.126 × 10⁹⁸(99-digit number)
31262249294543294349…42092246736747391999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
6.252 × 10⁹⁸(99-digit number)
62524498589086588699…84184493473494783999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.250 × 10⁹⁹(100-digit number)
12504899717817317739…68368986946989567999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.500 × 10⁹⁹(100-digit number)
25009799435634635479…36737973893979135999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.001 × 10⁹⁹(100-digit number)
50019598871269270959…73475947787958271999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.000 × 10¹⁰⁰(101-digit number)
10003919774253854191…46951895575916543999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.000 × 10¹⁰⁰(101-digit number)
20007839548507708383…93903791151833087999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.001 × 10¹⁰⁰(101-digit number)
40015679097015416767…87807582303666175999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
8.003 × 10¹⁰⁰(101-digit number)
80031358194030833535…75615164607332351999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.600 × 10¹⁰¹(102-digit number)
16006271638806166707…51230329214664703999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
3.201 × 10¹⁰¹(102-digit number)
32012543277612333414…02460658429329407999
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,692,922 XPM·at block #6,806,105 · 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.