Block #316,238

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/16/2013, 11:08:51 PM · Difficulty 10.1300 · 6,479,731 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
b9fd6e12970e0b81f5cf56d5ca1f91977dda5a7528c23a217a909ac06d695dce

Height

#316,238

Difficulty

10.129990

Transactions

8

Size

1.88 KB

Version

2

Bits

0a2146fe

Nonce

291,059

Timestamp

12/16/2013, 11:08:51 PM

Confirmations

6,479,731

Merkle Root

7579a2aa0e54c45ee07c6c4f1577d0a961336492950163f1d3bc181f09421ad1
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.

1.009 × 10¹⁰⁷(108-digit number)
10092366559305788315…13063477768530717119
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
1.009 × 10¹⁰⁷(108-digit number)
10092366559305788315…13063477768530717119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.018 × 10¹⁰⁷(108-digit number)
20184733118611576631…26126955537061434239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.036 × 10¹⁰⁷(108-digit number)
40369466237223153262…52253911074122868479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.073 × 10¹⁰⁷(108-digit number)
80738932474446306524…04507822148245736959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.614 × 10¹⁰⁸(109-digit number)
16147786494889261304…09015644296491473919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.229 × 10¹⁰⁸(109-digit number)
32295572989778522609…18031288592982947839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.459 × 10¹⁰⁸(109-digit number)
64591145979557045219…36062577185965895679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.291 × 10¹⁰⁹(110-digit number)
12918229195911409043…72125154371931791359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.583 × 10¹⁰⁹(110-digit number)
25836458391822818087…44250308743863582719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
5.167 × 10¹⁰⁹(110-digit number)
51672916783645636175…88500617487727165439
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:57,611,844 XPM·at block #6,795,968 · updates every 60s
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