Block #2,849,575

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 9/21/2018, 6:29:38 PM · Difficulty 11.7310 · 3,993,760 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
319c2cc521f3d56e6e2faafdb1d3b562ed8a8e73fb3491ac1d2fbe2335db76f2

Height

#2,849,575

Difficulty

11.731048

Transactions

26

Size

8.09 KB

Version

2

Bits

0bbb25f4

Nonce

558,292,196

Timestamp

9/21/2018, 6:29:38 PM

Confirmations

3,993,760

Merkle Root

2ebda306a26289960e8473581db808c1cdb6d4c63c397fc19285cc720cff31c9
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.

1.967 × 10⁹⁵(96-digit number)
19674426407163099595…43710492581556259839
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
1.967 × 10⁹⁵(96-digit number)
19674426407163099595…43710492581556259839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.934 × 10⁹⁵(96-digit number)
39348852814326199191…87420985163112519679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
7.869 × 10⁹⁵(96-digit number)
78697705628652398382…74841970326225039359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.573 × 10⁹⁶(97-digit number)
15739541125730479676…49683940652450078719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.147 × 10⁹⁶(97-digit number)
31479082251460959353…99367881304900157439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.295 × 10⁹⁶(97-digit number)
62958164502921918706…98735762609800314879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.259 × 10⁹⁷(98-digit number)
12591632900584383741…97471525219600629759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.518 × 10⁹⁷(98-digit number)
25183265801168767482…94943050439201259519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.036 × 10⁹⁷(98-digit number)
50366531602337534964…89886100878402519039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.007 × 10⁹⁸(99-digit number)
10073306320467506992…79772201756805038079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
2.014 × 10⁹⁸(99-digit number)
20146612640935013985…59544403513610076159
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:57,991,042 XPM·at block #6,843,334 · updates every 60s
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