Block #323,103

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/21/2013, 10:36:57 AM · Difficulty 10.2011 · 6,486,511 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
f3222cc5e8d0b09d007453acedfa4458879d9032c27222871b25a999aefe7a7a

Height

#323,103

Difficulty

10.201101

Transactions

19

Size

5.81 KB

Version

2

Bits

0a337b5f

Nonce

179,874

Timestamp

12/21/2013, 10:36:57 AM

Confirmations

6,486,511

Merkle Root

371805a44e3892baef81a457cdd184d6b6905334d384f49fccd69f66e80016de
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.

8.873 × 10⁹⁹(100-digit number)
88739124577112022016…21870474775310080001
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
8.873 × 10⁹⁹(100-digit number)
88739124577112022016…21870474775310080001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.774 × 10¹⁰⁰(101-digit number)
17747824915422404403…43740949550620160001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.549 × 10¹⁰⁰(101-digit number)
35495649830844808806…87481899101240320001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
7.099 × 10¹⁰⁰(101-digit number)
70991299661689617613…74963798202480640001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.419 × 10¹⁰¹(102-digit number)
14198259932337923522…49927596404961280001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.839 × 10¹⁰¹(102-digit number)
28396519864675847045…99855192809922560001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.679 × 10¹⁰¹(102-digit number)
56793039729351694090…99710385619845120001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.135 × 10¹⁰²(103-digit number)
11358607945870338818…99420771239690240001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.271 × 10¹⁰²(103-digit number)
22717215891740677636…98841542479380480001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.543 × 10¹⁰²(103-digit number)
45434431783481355272…97683084958760960001
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:57,720,989 XPM·at block #6,809,613 · updates every 60s
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