Block #536,150

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/11/2014, 7:24:25 AM · Difficulty 10.9078 · 6,266,077 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
2cb18a252e1e4ec66d9e95129d390330f1795f2dcba81a43fdab4c89b51eba44

Height

#536,150

Difficulty

10.907786

Transactions

4

Size

1.30 KB

Version

2

Bits

0ae864af

Nonce

66,297

Timestamp

5/11/2014, 7:24:25 AM

Confirmations

6,266,077

Merkle Root

b0d1fc3d7ccc40e5ba6ade3480ebffb8214f6d99a1484b9031a6ce212c12e897
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.

7.889 × 10⁹⁷(98-digit number)
78892157723881846238…10986032293661785341
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
7.889 × 10⁹⁷(98-digit number)
78892157723881846238…10986032293661785341
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.577 × 10⁹⁸(99-digit number)
15778431544776369247…21972064587323570681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.155 × 10⁹⁸(99-digit number)
31556863089552738495…43944129174647141361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.311 × 10⁹⁸(99-digit number)
63113726179105476990…87888258349294282721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.262 × 10⁹⁹(100-digit number)
12622745235821095398…75776516698588565441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.524 × 10⁹⁹(100-digit number)
25245490471642190796…51553033397177130881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.049 × 10⁹⁹(100-digit number)
50490980943284381592…03106066794354261761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.009 × 10¹⁰⁰(101-digit number)
10098196188656876318…06212133588708523521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.019 × 10¹⁰⁰(101-digit number)
20196392377313752637…12424267177417047041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.039 × 10¹⁰⁰(101-digit number)
40392784754627505274…24848534354834094081
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:57,661,823 XPM·at block #6,802,226 · updates every 60s
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