Block #782,921

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 10/25/2014, 8:23:32 PM · Difficulty 10.9750 · 6,021,092 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
334b20d3a93d19dd80ced2853df9d0ee6688cd06b2240faea1c42a13a6c6cbca

Height

#782,921

Difficulty

10.975013

Transactions

4

Size

13.72 KB

Version

2

Bits

0af99a76

Nonce

44,838,205

Timestamp

10/25/2014, 8:23:32 PM

Confirmations

6,021,092

Merkle Root

55ecc839fa9aac6d4540656e53d28ce46d914e7aa1e45bfb14d2d79f6d66a615
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.

6.280 × 10⁹⁶(97-digit number)
62800117763819991831…20643806119406623999
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
6.280 × 10⁹⁶(97-digit number)
62800117763819991831…20643806119406623999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.256 × 10⁹⁷(98-digit number)
12560023552763998366…41287612238813247999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.512 × 10⁹⁷(98-digit number)
25120047105527996732…82575224477626495999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.024 × 10⁹⁷(98-digit number)
50240094211055993465…65150448955252991999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.004 × 10⁹⁸(99-digit number)
10048018842211198693…30300897910505983999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.009 × 10⁹⁸(99-digit number)
20096037684422397386…60601795821011967999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.019 × 10⁹⁸(99-digit number)
40192075368844794772…21203591642023935999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.038 × 10⁹⁸(99-digit number)
80384150737689589544…42407183284047871999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.607 × 10⁹⁹(100-digit number)
16076830147537917908…84814366568095743999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.215 × 10⁹⁹(100-digit number)
32153660295075835817…69628733136191487999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
6.430 × 10⁹⁹(100-digit number)
64307320590151671635…39257466272382975999
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:57,676,152 XPM·at block #6,804,012 · updates every 60s
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