Block #597,700

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 6/22/2014, 4:33:57 AM · Difficulty 10.9313 · 6,198,562 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
386ec6fe75b8ef78bbc1e39a768ae081039e547e5c876d2d297fa132a48cf151

Height

#597,700

Difficulty

10.931268

Transactions

5

Size

1.09 KB

Version

2

Bits

0aee678e

Nonce

182,277,250

Timestamp

6/22/2014, 4:33:57 AM

Confirmations

6,198,562

Merkle Root

36e6ff4f7966197da0c343ffa46ba4696b011f565e17c2b7199be48f82a2fd23
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.

1.015 × 10⁹⁹(100-digit number)
10156357116180601203…35888952127938678401
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
1.015 × 10⁹⁹(100-digit number)
10156357116180601203…35888952127938678401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.031 × 10⁹⁹(100-digit number)
20312714232361202407…71777904255877356801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.062 × 10⁹⁹(100-digit number)
40625428464722404815…43555808511754713601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.125 × 10⁹⁹(100-digit number)
81250856929444809631…87111617023509427201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.625 × 10¹⁰⁰(101-digit number)
16250171385888961926…74223234047018854401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.250 × 10¹⁰⁰(101-digit number)
32500342771777923852…48446468094037708801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
6.500 × 10¹⁰⁰(101-digit number)
65000685543555847704…96892936188075417601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.300 × 10¹⁰¹(102-digit number)
13000137108711169540…93785872376150835201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.600 × 10¹⁰¹(102-digit number)
26000274217422339081…87571744752301670401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.200 × 10¹⁰¹(102-digit number)
52000548434844678163…75143489504603340801
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:57,614,095 XPM·at block #6,796,261 · updates every 60s
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