Block #744,820

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 9/28/2014, 1:06:04 PM · Difficulty 10.9794 · 6,053,772 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
fa6c02c0f3dadb451b2d4eaf0704e89f424b4b751171dfc831bfacdc749ff921

Height

#744,820

Difficulty

10.979362

Transactions

4

Size

1.04 KB

Version

2

Bits

0afab770

Nonce

133,451,968

Timestamp

9/28/2014, 1:06:04 PM

Confirmations

6,053,772

Merkle Root

eec6ac8d1fd306a5ed6edc6554bb39e03d8148056273d6208893d9efe653319b
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.

5.413 × 10⁹⁴(95-digit number)
54133724047022488913…56119688301787069999
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
5.413 × 10⁹⁴(95-digit number)
54133724047022488913…56119688301787069999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.082 × 10⁹⁵(96-digit number)
10826744809404497782…12239376603574139999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.165 × 10⁹⁵(96-digit number)
21653489618808995565…24478753207148279999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.330 × 10⁹⁵(96-digit number)
43306979237617991130…48957506414296559999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
8.661 × 10⁹⁵(96-digit number)
86613958475235982260…97915012828593119999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.732 × 10⁹⁶(97-digit number)
17322791695047196452…95830025657186239999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.464 × 10⁹⁶(97-digit number)
34645583390094392904…91660051314372479999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.929 × 10⁹⁶(97-digit number)
69291166780188785808…83320102628744959999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.385 × 10⁹⁷(98-digit number)
13858233356037757161…66640205257489919999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.771 × 10⁹⁷(98-digit number)
27716466712075514323…33280410514979839999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
5.543 × 10⁹⁷(98-digit number)
55432933424151028646…66560821029959679999
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 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
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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,632,749 XPM·at block #6,798,591 · updates every 60s
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