Block #792,873

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 11/1/2014, 11:13:28 PM · Difficulty 10.9739 · 5,999,589 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
83eb8dc81e8476471f9e73f66b5b3ebb84a59dc353f940c10487694a509a7b2e

Height

#792,873

Difficulty

10.973879

Transactions

4

Size

1.15 KB

Version

2

Bits

0af9502a

Nonce

197,816,727

Timestamp

11/1/2014, 11:13:28 PM

Confirmations

5,999,589

Merkle Root

e43c1a546aba5efaf4194a7d7b5ea92f8abb03bd0454c8d06ab1ae559ffccbd3
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.

1.396 × 10⁹⁴(95-digit number)
13962572595424727267…41178171531032019401
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
1.396 × 10⁹⁴(95-digit number)
13962572595424727267…41178171531032019401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.792 × 10⁹⁴(95-digit number)
27925145190849454534…82356343062064038801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.585 × 10⁹⁴(95-digit number)
55850290381698909068…64712686124128077601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.117 × 10⁹⁵(96-digit number)
11170058076339781813…29425372248256155201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.234 × 10⁹⁵(96-digit number)
22340116152679563627…58850744496512310401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.468 × 10⁹⁵(96-digit number)
44680232305359127254…17701488993024620801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
8.936 × 10⁹⁵(96-digit number)
89360464610718254509…35402977986049241601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.787 × 10⁹⁶(97-digit number)
17872092922143650901…70805955972098483201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.574 × 10⁹⁶(97-digit number)
35744185844287301803…41611911944196966401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
7.148 × 10⁹⁶(97-digit number)
71488371688574603607…83223823888393932801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
1.429 × 10⁹⁷(98-digit number)
14297674337714920721…66447647776787865601
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 Second 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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,583,657 XPM·at block #6,792,461 · updates every 60s
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