Block #329,449

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/25/2013, 11:31:32 PM · Difficulty 10.1715 · 6,465,401 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
2a23dd7b7f4958af0cbede1d815ce1c66596c60c51a76a91d06102d988e09f1b

Height

#329,449

Difficulty

10.171494

Transactions

29

Size

17.04 KB

Version

2

Bits

0a2be710

Nonce

3,857

Timestamp

12/25/2013, 11:31:32 PM

Confirmations

6,465,401

Merkle Root

ccb1690dfe5c1c03731b214e244ca4457acb4c78512bba481886297927631c4d
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.

1.317 × 10⁹⁸(99-digit number)
13173514777019750728…90490928202134367999
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
1.317 × 10⁹⁸(99-digit number)
13173514777019750728…90490928202134367999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.634 × 10⁹⁸(99-digit number)
26347029554039501456…80981856404268735999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.269 × 10⁹⁸(99-digit number)
52694059108079002913…61963712808537471999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.053 × 10⁹⁹(100-digit number)
10538811821615800582…23927425617074943999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.107 × 10⁹⁹(100-digit number)
21077623643231601165…47854851234149887999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.215 × 10⁹⁹(100-digit number)
42155247286463202331…95709702468299775999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
8.431 × 10⁹⁹(100-digit number)
84310494572926404662…91419404936599551999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.686 × 10¹⁰⁰(101-digit number)
16862098914585280932…82838809873199103999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.372 × 10¹⁰⁰(101-digit number)
33724197829170561864…65677619746398207999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
6.744 × 10¹⁰⁰(101-digit number)
67448395658341123729…31355239492796415999
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:57,602,829 XPM·at block #6,794,849 · updates every 60s
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