Block #602,824

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 6/26/2014, 2:06:42 PM · Difficulty 10.9129 · 6,203,917 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
7f63f0e9198287d3a2b5399cca01b488576dfcc7d15d19fc53de9833e8b87c95

Height

#602,824

Difficulty

10.912856

Transactions

5

Size

1.23 KB

Version

2

Bits

0ae9b0f6

Nonce

1,274,342,466

Timestamp

6/26/2014, 2:06:42 PM

Confirmations

6,203,917

Merkle Root

95a1496021d38fdf720595ad7a011086deae65652da72ff4e406a8813bfb4046
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.

1.246 × 10⁹⁷(98-digit number)
12469588114046780646…10883171616106730451
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
1.246 × 10⁹⁷(98-digit number)
12469588114046780646…10883171616106730451
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.493 × 10⁹⁷(98-digit number)
24939176228093561292…21766343232213460901
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.987 × 10⁹⁷(98-digit number)
49878352456187122584…43532686464426921801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
9.975 × 10⁹⁷(98-digit number)
99756704912374245168…87065372928853843601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.995 × 10⁹⁸(99-digit number)
19951340982474849033…74130745857707687201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.990 × 10⁹⁸(99-digit number)
39902681964949698067…48261491715415374401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.980 × 10⁹⁸(99-digit number)
79805363929899396135…96522983430830748801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.596 × 10⁹⁹(100-digit number)
15961072785979879227…93045966861661497601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.192 × 10⁹⁹(100-digit number)
31922145571959758454…86091933723322995201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
6.384 × 10⁹⁹(100-digit number)
63844291143919516908…72183867446645990401
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:57,698,025 XPM·at block #6,806,740 · updates every 60s
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