Block #460,536

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/26/2014, 2:25:25 AM · Difficulty 10.4162 · 6,344,311 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
3adf3ac8f6b720ccd36609a80b785a04881c99a678540025f0ac7725bc5af601

Height

#460,536

Difficulty

10.416161

Transactions

9

Size

48.49 KB

Version

2

Bits

0a6a8985

Nonce

165,351

Timestamp

3/26/2014, 2:25:25 AM

Confirmations

6,344,311

Merkle Root

02f2fc203a55ba28fd30c6b127117e5261556212db91f34b31c3fa3a6bd9faf1
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.

1.722 × 10⁹⁶(97-digit number)
17226166545655719816…29326381256828708741
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
1.722 × 10⁹⁶(97-digit number)
17226166545655719816…29326381256828708741
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.445 × 10⁹⁶(97-digit number)
34452333091311439632…58652762513657417481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
6.890 × 10⁹⁶(97-digit number)
68904666182622879264…17305525027314834961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.378 × 10⁹⁷(98-digit number)
13780933236524575852…34611050054629669921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.756 × 10⁹⁷(98-digit number)
27561866473049151705…69222100109259339841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.512 × 10⁹⁷(98-digit number)
55123732946098303411…38444200218518679681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.102 × 10⁹⁸(99-digit number)
11024746589219660682…76888400437037359361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.204 × 10⁹⁸(99-digit number)
22049493178439321364…53776800874074718721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.409 × 10⁹⁸(99-digit number)
44098986356878642729…07553601748149437441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
8.819 × 10⁹⁸(99-digit number)
88197972713757285459…15107203496298874881
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:57,682,847 XPM·at block #6,804,846 · updates every 60s
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