Block #2,114,370

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 5/13/2017, 2:38:08 PM · Difficulty 10.9001 · 4,728,849 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
25bb1e38cf61d874d96e14acdda33b0377e52b39e5a7469388cbdb6c1d61eb46

Height

#2,114,370

Difficulty

10.900120

Transactions

2

Size

1.86 KB

Version

2

Bits

0ae66e3f

Nonce

240,095,088

Timestamp

5/13/2017, 2:38:08 PM

Confirmations

4,728,849

Merkle Root

3bc721924535c78a628c2d2c053d731411ceb107819fff753b2aedcffb445803
Transactions (2)
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.

1.804 × 10⁹⁶(97-digit number)
18049893029736474637…99675887018280161281
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
1.804 × 10⁹⁶(97-digit number)
18049893029736474637…99675887018280161281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.609 × 10⁹⁶(97-digit number)
36099786059472949275…99351774036560322561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
7.219 × 10⁹⁶(97-digit number)
72199572118945898550…98703548073120645121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.443 × 10⁹⁷(98-digit number)
14439914423789179710…97407096146241290241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.887 × 10⁹⁷(98-digit number)
28879828847578359420…94814192292482580481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.775 × 10⁹⁷(98-digit number)
57759657695156718840…89628384584965160961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.155 × 10⁹⁸(99-digit number)
11551931539031343768…79256769169930321921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.310 × 10⁹⁸(99-digit number)
23103863078062687536…58513538339860643841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.620 × 10⁹⁸(99-digit number)
46207726156125375072…17027076679721287681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
9.241 × 10⁹⁸(99-digit number)
92415452312250750144…34054153359442575361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
1.848 × 10⁹⁹(100-digit number)
18483090462450150028…68108306718885150721
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,990,125 XPM·at block #6,843,218 · updates every 60s
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