Block #339,161

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/1/2014, 9:59:09 PM · Difficulty 10.1290 · 6,464,338 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
be9648d91b559dd28a68da739cf75ee316c11501eec5a45d51791c97a129bc96

Height

#339,161

Difficulty

10.129042

Transactions

4

Size

1.68 KB

Version

2

Bits

0a2108e5

Nonce

9,939

Timestamp

1/1/2014, 9:59:09 PM

Confirmations

6,464,338

Merkle Root

893cda75aac3079bd0db369816c211be3c94cc8ea2ea07145d07b3ccabe3c45d
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.

5.805 × 10⁹⁸(99-digit number)
58055124936234115059…18822629964588428801
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
5.805 × 10⁹⁸(99-digit number)
58055124936234115059…18822629964588428801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.161 × 10⁹⁹(100-digit number)
11611024987246823011…37645259929176857601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.322 × 10⁹⁹(100-digit number)
23222049974493646023…75290519858353715201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.644 × 10⁹⁹(100-digit number)
46444099948987292047…50581039716707430401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
9.288 × 10⁹⁹(100-digit number)
92888199897974584094…01162079433414860801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.857 × 10¹⁰⁰(101-digit number)
18577639979594916818…02324158866829721601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.715 × 10¹⁰⁰(101-digit number)
37155279959189833637…04648317733659443201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
7.431 × 10¹⁰⁰(101-digit number)
74310559918379667275…09296635467318886401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.486 × 10¹⁰¹(102-digit number)
14862111983675933455…18593270934637772801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.972 × 10¹⁰¹(102-digit number)
29724223967351866910…37186541869275545601
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:57,672,023 XPM·at block #6,803,498 · updates every 60s
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