Block #539,602

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/12/2014, 7:14:07 PM · Difficulty 10.9289 · 6,256,347 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
dacb47c0293589f47670ae842fe7a78e7016e74161593178a4961cb85fb30efd

Height

#539,602

Difficulty

10.928896

Transactions

7

Size

2.36 KB

Version

2

Bits

0aedcc29

Nonce

51,369,866

Timestamp

5/12/2014, 7:14:07 PM

Confirmations

6,256,347

Merkle Root

f5a192d8e541b265555d7a9e6ede9f7229090284eeff57ae45253a1c3f0549b5
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.

6.807 × 10⁹⁸(99-digit number)
68074985657751885406…26938032322667054081
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
6.807 × 10⁹⁸(99-digit number)
68074985657751885406…26938032322667054081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.361 × 10⁹⁹(100-digit number)
13614997131550377081…53876064645334108161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.722 × 10⁹⁹(100-digit number)
27229994263100754162…07752129290668216321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.445 × 10⁹⁹(100-digit number)
54459988526201508325…15504258581336432641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.089 × 10¹⁰⁰(101-digit number)
10891997705240301665…31008517162672865281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.178 × 10¹⁰⁰(101-digit number)
21783995410480603330…62017034325345730561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.356 × 10¹⁰⁰(101-digit number)
43567990820961206660…24034068650691461121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
8.713 × 10¹⁰⁰(101-digit number)
87135981641922413320…48068137301382922241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.742 × 10¹⁰¹(102-digit number)
17427196328384482664…96136274602765844481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.485 × 10¹⁰¹(102-digit number)
34854392656768965328…92272549205531688961
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:57,611,681 XPM·at block #6,795,948 · updates every 60s
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