Block #562,812

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 5/26/2014, 11:59:13 AM · Difficulty 10.9650 · 6,241,265 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
48af291903cd0725fd86410044c47b04eee8ef85b16a10d4f679faf169361ceb

Height

#562,812

Difficulty

10.965016

Transactions

8

Size

2.04 KB

Version

2

Bits

0af70b52

Nonce

39,633,427

Timestamp

5/26/2014, 11:59:13 AM

Confirmations

6,241,265

Merkle Root

2779a2a53b44ec9854910dafb6a9d9b4c070f07c0e6db56a15f9f7ff5e42e9a4
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.

1.150 × 10⁹⁹(100-digit number)
11506650516708987611…37271804979260794881
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
1.150 × 10⁹⁹(100-digit number)
11506650516708987611…37271804979260794881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.301 × 10⁹⁹(100-digit number)
23013301033417975223…74543609958521589761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.602 × 10⁹⁹(100-digit number)
46026602066835950447…49087219917043179521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
9.205 × 10⁹⁹(100-digit number)
92053204133671900894…98174439834086359041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.841 × 10¹⁰⁰(101-digit number)
18410640826734380178…96348879668172718081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.682 × 10¹⁰⁰(101-digit number)
36821281653468760357…92697759336345436161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.364 × 10¹⁰⁰(101-digit number)
73642563306937520715…85395518672690872321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.472 × 10¹⁰¹(102-digit number)
14728512661387504143…70791037345381744641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.945 × 10¹⁰¹(102-digit number)
29457025322775008286…41582074690763489281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.891 × 10¹⁰¹(102-digit number)
58914050645550016572…83164149381526978561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
1.178 × 10¹⁰²(103-digit number)
11782810129110003314…66328298763053957121
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,676,665 XPM·at block #6,804,076 · updates every 60s
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