Block #511,086

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/26/2014, 12:56:01 AM · Difficulty 10.8286 · 6,295,092 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
dabd2fe85a3077e36332ba9ae506b7094114c3ddb835dc26a8a6cf7b408ec636

Height

#511,086

Difficulty

10.828600

Transactions

2

Size

1.20 KB

Version

2

Bits

0ad41f24

Nonce

140,675,166

Timestamp

4/26/2014, 12:56:01 AM

Confirmations

6,295,092

Merkle Root

128740fd02ffc0689e9ffa45f2af02a26c7da77351602de126a3ed062a415c02
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.

8.696 × 10⁹⁸(99-digit number)
86965275458594104837…23862757583695748001
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
8.696 × 10⁹⁸(99-digit number)
86965275458594104837…23862757583695748001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.739 × 10⁹⁹(100-digit number)
17393055091718820967…47725515167391496001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.478 × 10⁹⁹(100-digit number)
34786110183437641934…95451030334782992001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.957 × 10⁹⁹(100-digit number)
69572220366875283869…90902060669565984001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.391 × 10¹⁰⁰(101-digit number)
13914444073375056773…81804121339131968001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.782 × 10¹⁰⁰(101-digit number)
27828888146750113547…63608242678263936001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.565 × 10¹⁰⁰(101-digit number)
55657776293500227095…27216485356527872001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.113 × 10¹⁰¹(102-digit number)
11131555258700045419…54432970713055744001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.226 × 10¹⁰¹(102-digit number)
22263110517400090838…08865941426111488001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.452 × 10¹⁰¹(102-digit number)
44526221034800181676…17731882852222976001
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:57,693,508 XPM·at block #6,806,177 · updates every 60s
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