Block #374,859

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/25/2014, 8:28:24 AM · Difficulty 10.4185 · 6,432,514 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
7ab19a3cfca538826f0792689a6ccec66d3cfffa1a4215cea9bd3d2139177863

Height

#374,859

Difficulty

10.418460

Transactions

5

Size

2.10 KB

Version

2

Bits

0a6b2032

Nonce

30,315

Timestamp

1/25/2014, 8:28:24 AM

Confirmations

6,432,514

Merkle Root

53e9cb2c19c4e7b47ceb6e4e7f1e48dc0667ffce6ffbf7dcd7e92fd23e248806
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.

2.581 × 10⁹⁶(97-digit number)
25812338713304887019…20665178904478122879
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
2.581 × 10⁹⁶(97-digit number)
25812338713304887019…20665178904478122879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
5.162 × 10⁹⁶(97-digit number)
51624677426609774038…41330357808956245759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.032 × 10⁹⁷(98-digit number)
10324935485321954807…82660715617912491519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.064 × 10⁹⁷(98-digit number)
20649870970643909615…65321431235824983039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.129 × 10⁹⁷(98-digit number)
41299741941287819230…30642862471649966079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
8.259 × 10⁹⁷(98-digit number)
82599483882575638461…61285724943299932159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.651 × 10⁹⁸(99-digit number)
16519896776515127692…22571449886599864319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.303 × 10⁹⁸(99-digit number)
33039793553030255384…45142899773199728639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.607 × 10⁹⁸(99-digit number)
66079587106060510769…90285799546399457279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.321 × 10⁹⁹(100-digit number)
13215917421212102153…80571599092798914559
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:57,703,006 XPM·at block #6,807,372 · updates every 60s
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