Block #2,914,195

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 11/7/2018, 11:31:15 PM · Difficulty 11.4795 · 3,917,136 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
08144f6f0752188c257bbaa5aa638758e0af0b79cccbf2f5f6220dcb3a92fd61

Height

#2,914,195

Difficulty

11.479495

Transactions

2

Size

872 B

Version

2

Bits

0b7ac02e

Nonce

489,312,470

Timestamp

11/7/2018, 11:31:15 PM

Confirmations

3,917,136

Merkle Root

28bda384e81e79d39da6353d4348621e8cf74f87ffe6f15c63e36354b869184b
Transactions (2)
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.

4.041 × 10⁹⁴(95-digit number)
40411250346103991806…20413829450184769539
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
4.041 × 10⁹⁴(95-digit number)
40411250346103991806…20413829450184769539
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.082 × 10⁹⁴(95-digit number)
80822500692207983613…40827658900369539079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.616 × 10⁹⁵(96-digit number)
16164500138441596722…81655317800739078159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.232 × 10⁹⁵(96-digit number)
32329000276883193445…63310635601478156319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.465 × 10⁹⁵(96-digit number)
64658000553766386890…26621271202956312639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.293 × 10⁹⁶(97-digit number)
12931600110753277378…53242542405912625279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.586 × 10⁹⁶(97-digit number)
25863200221506554756…06485084811825250559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.172 × 10⁹⁶(97-digit number)
51726400443013109512…12970169623650501119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.034 × 10⁹⁷(98-digit number)
10345280088602621902…25940339247301002239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.069 × 10⁹⁷(98-digit number)
20690560177205243805…51880678494602004479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
4.138 × 10⁹⁷(98-digit number)
41381120354410487610…03761356989204008959
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:57,894,801 XPM·at block #6,831,330 · updates every 60s
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