Block #424,628

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/1/2014, 8:43:04 AM · Difficulty 10.3601 · 6,388,024 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
ea25f7590c086b7dc6e1d8fb99fe65810ac372dce07b03e27469a510eb8a9d2e

Height

#424,628

Difficulty

10.360117

Transactions

4

Size

1.57 KB

Version

2

Bits

0a5c30a5

Nonce

13,008

Timestamp

3/1/2014, 8:43:04 AM

Confirmations

6,388,024

Merkle Root

1bc9c57c1235681f2733b8433c41c7504deacf68f6700ec0e627b1e80e1eb6f2
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.

8.113 × 10⁹⁴(95-digit number)
81138104058048778195…08182596435218186459
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
8.113 × 10⁹⁴(95-digit number)
81138104058048778195…08182596435218186459
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.622 × 10⁹⁵(96-digit number)
16227620811609755639…16365192870436372919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.245 × 10⁹⁵(96-digit number)
32455241623219511278…32730385740872745839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
6.491 × 10⁹⁵(96-digit number)
64910483246439022556…65460771481745491679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.298 × 10⁹⁶(97-digit number)
12982096649287804511…30921542963490983359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.596 × 10⁹⁶(97-digit number)
25964193298575609022…61843085926981966719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.192 × 10⁹⁶(97-digit number)
51928386597151218045…23686171853963933439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.038 × 10⁹⁷(98-digit number)
10385677319430243609…47372343707927866879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.077 × 10⁹⁷(98-digit number)
20771354638860487218…94744687415855733759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.154 × 10⁹⁷(98-digit number)
41542709277720974436…89489374831711467519
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:57,745,245 XPM·at block #6,812,651 · updates every 60s
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