Block #465,664

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/29/2014, 3:07:27 PM · Difficulty 10.4241 · 6,329,153 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
b084b82e434a5f00b14205244cfa46a3d7ae5e40a505b87056edbc81a7bb90b0

Height

#465,664

Difficulty

10.424098

Transactions

8

Size

2.17 KB

Version

2

Bits

0a6c91b8

Nonce

202,092

Timestamp

3/29/2014, 3:07:27 PM

Confirmations

6,329,153

Merkle Root

40211ed7ffcee751b12c199f75d3428e1b4ff881100bbf4face47a7e3e76341a
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.

3.146 × 10⁹⁶(97-digit number)
31460857208529994322…51563643304585206401
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
3.146 × 10⁹⁶(97-digit number)
31460857208529994322…51563643304585206401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.292 × 10⁹⁶(97-digit number)
62921714417059988644…03127286609170412801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.258 × 10⁹⁷(98-digit number)
12584342883411997728…06254573218340825601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.516 × 10⁹⁷(98-digit number)
25168685766823995457…12509146436681651201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.033 × 10⁹⁷(98-digit number)
50337371533647990915…25018292873363302401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.006 × 10⁹⁸(99-digit number)
10067474306729598183…50036585746726604801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.013 × 10⁹⁸(99-digit number)
20134948613459196366…00073171493453209601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.026 × 10⁹⁸(99-digit number)
40269897226918392732…00146342986906419201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
8.053 × 10⁹⁸(99-digit number)
80539794453836785464…00292685973812838401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.610 × 10⁹⁹(100-digit number)
16107958890767357092…00585371947625676801
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:57,602,583 XPM·at block #6,794,816 · updates every 60s
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