Block #563,052

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/26/2014, 4:40:30 PM · Difficulty 10.9647 · 6,240,248 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
756e17b7f613c74260601c52db332521ffdd77683788e6895e0d686e6b12e74e

Height

#563,052

Difficulty

10.964733

Transactions

2

Size

1.73 KB

Version

2

Bits

0af6f8c4

Nonce

182,146,615

Timestamp

5/26/2014, 4:40:30 PM

Confirmations

6,240,248

Merkle Root

404cb95faaa159470ae15a0295ab803b4aa3f8d64d44c6d2d03e9d96fe265244
Transactions (2)
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.

6.205 × 10⁹⁷(98-digit number)
62051724925912424232…29963746676464580001
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
6.205 × 10⁹⁷(98-digit number)
62051724925912424232…29963746676464580001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.241 × 10⁹⁸(99-digit number)
12410344985182484846…59927493352929160001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.482 × 10⁹⁸(99-digit number)
24820689970364969692…19854986705858320001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.964 × 10⁹⁸(99-digit number)
49641379940729939385…39709973411716640001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
9.928 × 10⁹⁸(99-digit number)
99282759881459878771…79419946823433280001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.985 × 10⁹⁹(100-digit number)
19856551976291975754…58839893646866560001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.971 × 10⁹⁹(100-digit number)
39713103952583951508…17679787293733120001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
7.942 × 10⁹⁹(100-digit number)
79426207905167903017…35359574587466240001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.588 × 10¹⁰⁰(101-digit number)
15885241581033580603…70719149174932480001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.177 × 10¹⁰⁰(101-digit number)
31770483162067161206…41438298349864960001
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:57,670,427 XPM·at block #6,803,299 · updates every 60s
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