Block #809,778

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 11/13/2014, 8:23:54 PM · Difficulty 10.9734 · 5,996,188 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
e43b876ba7d4e94884c5bb8e53480ad64146f7eb597093ed36f4211619df07b4

Height

#809,778

Difficulty

10.973370

Transactions

5

Size

1.37 KB

Version

2

Bits

0af92ec3

Nonce

361,694,345

Timestamp

11/13/2014, 8:23:54 PM

Confirmations

5,996,188

Merkle Root

f31889695aa5308e94c179bb58f6778084b318e5126b85169b82918f4c26f970
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.

9.445 × 10⁹⁴(95-digit number)
94451021809083501207…20319009171386829199
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
9.445 × 10⁹⁴(95-digit number)
94451021809083501207…20319009171386829199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.889 × 10⁹⁵(96-digit number)
18890204361816700241…40638018342773658399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.778 × 10⁹⁵(96-digit number)
37780408723633400482…81276036685547316799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
7.556 × 10⁹⁵(96-digit number)
75560817447266800965…62552073371094633599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.511 × 10⁹⁶(97-digit number)
15112163489453360193…25104146742189267199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.022 × 10⁹⁶(97-digit number)
30224326978906720386…50208293484378534399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.044 × 10⁹⁶(97-digit number)
60448653957813440772…00416586968757068799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.208 × 10⁹⁷(98-digit number)
12089730791562688154…00833173937514137599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.417 × 10⁹⁷(98-digit number)
24179461583125376309…01666347875028275199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.835 × 10⁹⁷(98-digit number)
48358923166250752618…03332695750056550399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
9.671 × 10⁹⁷(98-digit number)
96717846332501505236…06665391500113100799
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:57,691,802 XPM·at block #6,805,965 · updates every 60s
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