Block #324,928

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/22/2013, 4:27:10 PM · Difficulty 10.2066 · 6,477,849 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
1b570f540821e15796b4d67b8ebdeddea1751cfdb29c8ac2eed515715a6d50e7

Height

#324,928

Difficulty

10.206571

Transactions

2

Size

462 B

Version

2

Bits

0a34e1dd

Nonce

69,065

Timestamp

12/22/2013, 4:27:10 PM

Confirmations

6,477,849

Merkle Root

c0270625d49127b73172d3ffb4dd59044959b3a77ff2e17f7b178d065ac7f544
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.

2.571 × 10⁹⁷(98-digit number)
25719133181673444722…12260407508116019199
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
2.571 × 10⁹⁷(98-digit number)
25719133181673444722…12260407508116019199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
5.143 × 10⁹⁷(98-digit number)
51438266363346889444…24520815016232038399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.028 × 10⁹⁸(99-digit number)
10287653272669377888…49041630032464076799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.057 × 10⁹⁸(99-digit number)
20575306545338755777…98083260064928153599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.115 × 10⁹⁸(99-digit number)
41150613090677511555…96166520129856307199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
8.230 × 10⁹⁸(99-digit number)
82301226181355023111…92333040259712614399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.646 × 10⁹⁹(100-digit number)
16460245236271004622…84666080519425228799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.292 × 10⁹⁹(100-digit number)
32920490472542009244…69332161038850457599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.584 × 10⁹⁹(100-digit number)
65840980945084018489…38664322077700915199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.316 × 10¹⁰⁰(101-digit number)
13168196189016803697…77328644155401830399
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:57,666,240 XPM·at block #6,802,776 · updates every 60s
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