Block #363,394

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/17/2014, 9:31:20 AM · Difficulty 10.4135 · 6,442,453 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
3d0d1c7e4d45b8a0c9618661cb02a18e9dc272ecc58a099e8b4dda8579fc9833

Height

#363,394

Difficulty

10.413539

Transactions

5

Size

1.66 KB

Version

2

Bits

0a69ddb8

Nonce

146,851

Timestamp

1/17/2014, 9:31:20 AM

Confirmations

6,442,453

Merkle Root

bca352221df7718347b30726b3ddedccb81ab0ba8432bb5d25ebf3a65b136cd1
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.

2.058 × 10⁹⁸(99-digit number)
20584799306817388272…46922223566956866399
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
2.058 × 10⁹⁸(99-digit number)
20584799306817388272…46922223566956866399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.116 × 10⁹⁸(99-digit number)
41169598613634776545…93844447133913732799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.233 × 10⁹⁸(99-digit number)
82339197227269553090…87688894267827465599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.646 × 10⁹⁹(100-digit number)
16467839445453910618…75377788535654931199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.293 × 10⁹⁹(100-digit number)
32935678890907821236…50755577071309862399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.587 × 10⁹⁹(100-digit number)
65871357781815642472…01511154142619724799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.317 × 10¹⁰⁰(101-digit number)
13174271556363128494…03022308285239449599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.634 × 10¹⁰⁰(101-digit number)
26348543112726256988…06044616570478899199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.269 × 10¹⁰⁰(101-digit number)
52697086225452513977…12089233140957798399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.053 × 10¹⁰¹(102-digit number)
10539417245090502795…24178466281915596799
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 First 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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,690,856 XPM·at block #6,805,846 · updates every 60s
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