Block #329,474

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 12/26/2013, 12:04:52 AM · Difficulty 10.1702 · 6,466,155 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
5d17e14c4750b7341e52f3ba8a27efca86fd1c9f9e29c08c7f81c767f962fa9f

Height

#329,474

Difficulty

10.170229

Transactions

6

Size

1.27 KB

Version

2

Bits

0a2b9428

Nonce

96,596

Timestamp

12/26/2013, 12:04:52 AM

Confirmations

6,466,155

Merkle Root

f46cd78fac847dfe97e179f082bde45e781ba738fa1cc52c5cb9a275827f26b5
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.

4.413 × 10⁹⁸(99-digit number)
44136081344140269487…81754835136859710559
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
4.413 × 10⁹⁸(99-digit number)
44136081344140269487…81754835136859710559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.827 × 10⁹⁸(99-digit number)
88272162688280538974…63509670273719421119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.765 × 10⁹⁹(100-digit number)
17654432537656107794…27019340547438842239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.530 × 10⁹⁹(100-digit number)
35308865075312215589…54038681094877684479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
7.061 × 10⁹⁹(100-digit number)
70617730150624431179…08077362189755368959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.412 × 10¹⁰⁰(101-digit number)
14123546030124886235…16154724379510737919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.824 × 10¹⁰⁰(101-digit number)
28247092060249772471…32309448759021475839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.649 × 10¹⁰⁰(101-digit number)
56494184120499544943…64618897518042951679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.129 × 10¹⁰¹(102-digit number)
11298836824099908988…29237795036085903359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.259 × 10¹⁰¹(102-digit number)
22597673648199817977…58475590072171806719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
4.519 × 10¹⁰¹(102-digit number)
45195347296399635954…16951180144343613439
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:57,609,100 XPM·at block #6,795,628 · 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.