Block #472,604

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/3/2014, 9:24:21 AM · Difficulty 10.4370 · 6,323,149 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
b7f2747a4f897c407eeefd2e0a12f549ab98c8066b37ba7328d655810f4b4221

Height

#472,604

Difficulty

10.437003

Transactions

14

Size

21.84 KB

Version

2

Bits

0a6fdf69

Nonce

1,177

Timestamp

4/3/2014, 9:24:21 AM

Confirmations

6,323,149

Merkle Root

f6babe7bad35d1c7ab788db3e33f2c3e64c893ca1615941f04d3e278365735f9
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.

6.932 × 10⁹⁴(95-digit number)
69328491198128212613…36339990181019801641
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
6.932 × 10⁹⁴(95-digit number)
69328491198128212613…36339990181019801641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.386 × 10⁹⁵(96-digit number)
13865698239625642522…72679980362039603281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.773 × 10⁹⁵(96-digit number)
27731396479251285045…45359960724079206561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.546 × 10⁹⁵(96-digit number)
55462792958502570090…90719921448158413121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.109 × 10⁹⁶(97-digit number)
11092558591700514018…81439842896316826241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.218 × 10⁹⁶(97-digit number)
22185117183401028036…62879685792633652481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.437 × 10⁹⁶(97-digit number)
44370234366802056072…25759371585267304961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
8.874 × 10⁹⁶(97-digit number)
88740468733604112145…51518743170534609921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.774 × 10⁹⁷(98-digit number)
17748093746720822429…03037486341069219841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.549 × 10⁹⁷(98-digit number)
35496187493441644858…06074972682138439681
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 Second 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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,610,103 XPM·at block #6,795,752 · updates every 60s
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