Block #482,639

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/9/2014, 2:48:18 PM · Difficulty 10.5487 · 6,313,128 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
cb9f1c3f25eedc6fd4c618fa09afe2c39e95b0bc310f1154f7de15ac5baabcb0

Height

#482,639

Difficulty

10.548686

Transactions

7

Size

3.24 KB

Version

2

Bits

0a8c76aa

Nonce

66,552

Timestamp

4/9/2014, 2:48:18 PM

Confirmations

6,313,128

Merkle Root

1f1a133c442b1601aa46960e6c10dc6ce60dcdf8d84650192a69ddf5a126b145
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.

1.750 × 10¹⁰⁰(101-digit number)
17507285151503297730…06580230322383054901
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
1.750 × 10¹⁰⁰(101-digit number)
17507285151503297730…06580230322383054901
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.501 × 10¹⁰⁰(101-digit number)
35014570303006595460…13160460644766109801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
7.002 × 10¹⁰⁰(101-digit number)
70029140606013190920…26320921289532219601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.400 × 10¹⁰¹(102-digit number)
14005828121202638184…52641842579064439201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.801 × 10¹⁰¹(102-digit number)
28011656242405276368…05283685158128878401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.602 × 10¹⁰¹(102-digit number)
56023312484810552736…10567370316257756801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.120 × 10¹⁰²(103-digit number)
11204662496962110547…21134740632515513601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.240 × 10¹⁰²(103-digit number)
22409324993924221094…42269481265031027201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.481 × 10¹⁰²(103-digit number)
44818649987848442189…84538962530062054401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
8.963 × 10¹⁰²(103-digit number)
89637299975696884378…69077925060124108801
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:57,610,218 XPM·at block #6,795,766 · updates every 60s
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