Block #1,045,927

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/5/2015, 9:25:22 AM · Difficulty 10.7318 · 5,781,183 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
6c65d0d1910d34408f5d2d4f697ecf6b6ffce398c3e44ec9018e4e6de5c6c3cd

Height

#1,045,927

Difficulty

10.731770

Transactions

17

Size

3.23 KB

Version

2

Bits

0abb5545

Nonce

450,689,920

Timestamp

5/5/2015, 9:25:22 AM

Confirmations

5,781,183

Merkle Root

36a6f78f3b94e5206412259ec0d0badfa778608012f8fee8d0681974663cd2da
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.

1.158 × 10⁹⁷(98-digit number)
11589576302932982190…99897594133687458561
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
1.158 × 10⁹⁷(98-digit number)
11589576302932982190…99897594133687458561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.317 × 10⁹⁷(98-digit number)
23179152605865964380…99795188267374917121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.635 × 10⁹⁷(98-digit number)
46358305211731928761…99590376534749834241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
9.271 × 10⁹⁷(98-digit number)
92716610423463857523…99180753069499668481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.854 × 10⁹⁸(99-digit number)
18543322084692771504…98361506138999336961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.708 × 10⁹⁸(99-digit number)
37086644169385543009…96723012277998673921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.417 × 10⁹⁸(99-digit number)
74173288338771086018…93446024555997347841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.483 × 10⁹⁹(100-digit number)
14834657667754217203…86892049111994695681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.966 × 10⁹⁹(100-digit number)
29669315335508434407…73784098223989391361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.933 × 10⁹⁹(100-digit number)
59338630671016868814…47568196447978782721
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:57,861,059 XPM·at block #6,827,109 · updates every 60s
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