Block #578,288

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 6/5/2014, 10:48:10 PM · Difficulty 10.9683 · 6,224,379 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
9f8b2d80f7ca84e8a68e70a467b2aba898a36a1a8047fd0101e93e826de824ab

Height

#578,288

Difficulty

10.968325

Transactions

2

Size

1.58 KB

Version

2

Bits

0af7e421

Nonce

342,142,061

Timestamp

6/5/2014, 10:48:10 PM

Confirmations

6,224,379

Merkle Root

5c4ed812e58024573eba384419f809840ed6b001e707fa2d35e4ee3956616772
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.

3.453 × 10⁹⁹(100-digit number)
34531488742301054136…05080159975662878721
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
3.453 × 10⁹⁹(100-digit number)
34531488742301054136…05080159975662878721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.906 × 10⁹⁹(100-digit number)
69062977484602108273…10160319951325757441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.381 × 10¹⁰⁰(101-digit number)
13812595496920421654…20320639902651514881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.762 × 10¹⁰⁰(101-digit number)
27625190993840843309…40641279805303029761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.525 × 10¹⁰⁰(101-digit number)
55250381987681686618…81282559610606059521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.105 × 10¹⁰¹(102-digit number)
11050076397536337323…62565119221212119041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.210 × 10¹⁰¹(102-digit number)
22100152795072674647…25130238442424238081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.420 × 10¹⁰¹(102-digit number)
44200305590145349294…50260476884848476161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
8.840 × 10¹⁰¹(102-digit number)
88400611180290698589…00520953769696952321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.768 × 10¹⁰²(103-digit number)
17680122236058139717…01041907539393904641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
3.536 × 10¹⁰²(103-digit number)
35360244472116279435…02083815078787809281
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:57,665,355 XPM·at block #6,802,666 · updates every 60s
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