Block #530,595

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 5/7/2014, 11:25:36 PM · Difficulty 10.8926 · 6,274,473 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
7cb3c3173180323216eaedd45c9ab376419987c191233fb883511dbe79dc82f8

Height

#530,595

Difficulty

10.892604

Transactions

2

Size

1.03 KB

Version

2

Bits

0ae481b8

Nonce

4,380

Timestamp

5/7/2014, 11:25:36 PM

Confirmations

6,274,473

Merkle Root

d28f0d7df249cda2896d07e953ad912e0c7ceeb875136225b0fdaac656fff09e
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.

2.467 × 10⁹⁴(95-digit number)
24672825953271091393…02934916265116827521
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
2.467 × 10⁹⁴(95-digit number)
24672825953271091393…02934916265116827521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
4.934 × 10⁹⁴(95-digit number)
49345651906542182786…05869832530233655041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
9.869 × 10⁹⁴(95-digit number)
98691303813084365573…11739665060467310081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.973 × 10⁹⁵(96-digit number)
19738260762616873114…23479330120934620161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.947 × 10⁹⁵(96-digit number)
39476521525233746229…46958660241869240321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
7.895 × 10⁹⁵(96-digit number)
78953043050467492458…93917320483738480641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.579 × 10⁹⁶(97-digit number)
15790608610093498491…87834640967476961281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.158 × 10⁹⁶(97-digit number)
31581217220186996983…75669281934953922561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.316 × 10⁹⁶(97-digit number)
63162434440373993966…51338563869907845121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.263 × 10⁹⁷(98-digit number)
12632486888074798793…02677127739815690241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
2.526 × 10⁹⁷(98-digit number)
25264973776149597586…05354255479631380481
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:57,684,610 XPM·at block #6,805,067 · updates every 60s
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