Block #326,054

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/23/2013, 12:24:58 PM · Difficulty 10.1954 · 6,477,954 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
5be75d5f79d66ee60e71ec7eadd6bd379140f2673a38955f606e5977c3206377

Height

#326,054

Difficulty

10.195431

Transactions

14

Size

3.46 KB

Version

2

Bits

0a3207c7

Nonce

39,219

Timestamp

12/23/2013, 12:24:58 PM

Confirmations

6,477,954

Merkle Root

01c477b31fda002c565b0e38ac4459e8ef273a28d5e1ea5a702ae5922801989d
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.

5.616 × 10⁹⁸(99-digit number)
56167037571708941961…83759796897928860199
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
5.616 × 10⁹⁸(99-digit number)
56167037571708941961…83759796897928860199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.123 × 10⁹⁹(100-digit number)
11233407514341788392…67519593795857720399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.246 × 10⁹⁹(100-digit number)
22466815028683576784…35039187591715440799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.493 × 10⁹⁹(100-digit number)
44933630057367153569…70078375183430881599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
8.986 × 10⁹⁹(100-digit number)
89867260114734307139…40156750366861763199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.797 × 10¹⁰⁰(101-digit number)
17973452022946861427…80313500733723526399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.594 × 10¹⁰⁰(101-digit number)
35946904045893722855…60627001467447052799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
7.189 × 10¹⁰⁰(101-digit number)
71893808091787445711…21254002934894105599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.437 × 10¹⁰¹(102-digit number)
14378761618357489142…42508005869788211199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.875 × 10¹⁰¹(102-digit number)
28757523236714978284…85016011739576422399
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:57,676,112 XPM·at block #6,804,007 · updates every 60s
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