1. #6,804,0212CC12 primes

    Cunningham 2nd · ⛏️ coinsforall.io

Block #396,834

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 2/9/2014, 4:07:57 PM · Difficulty 10.4159 · 6,407,188 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
fd4d73acc9739dcb94f53ce34dad406b853976e6d9e8b6f28d856ef0e93f58ee

Height

#396,834

Difficulty

10.415854

Transactions

1

Size

209 B

Version

2

Bits

0a6a7568

Nonce

113,367

Timestamp

2/9/2014, 4:07:57 PM

Confirmations

6,407,188

Merkle Root

b072c5e357987ff4092ca7086e70abd171e2ed379d86d73744d6c29efc45a94e
Transactions (1)
1 in → 1 out9.2000 XPM116 B
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.

7.057 × 10¹⁰⁰(101-digit number)
70578040708234285207…58509489112859451499
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
7.057 × 10¹⁰⁰(101-digit number)
70578040708234285207…58509489112859451499
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.411 × 10¹⁰¹(102-digit number)
14115608141646857041…17018978225718902999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.823 × 10¹⁰¹(102-digit number)
28231216283293714083…34037956451437805999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.646 × 10¹⁰¹(102-digit number)
56462432566587428166…68075912902875611999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.129 × 10¹⁰²(103-digit number)
11292486513317485633…36151825805751223999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.258 × 10¹⁰²(103-digit number)
22584973026634971266…72303651611502447999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.516 × 10¹⁰²(103-digit number)
45169946053269942533…44607303223004895999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
9.033 × 10¹⁰²(103-digit number)
90339892106539885066…89214606446009791999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.806 × 10¹⁰³(104-digit number)
18067978421307977013…78429212892019583999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.613 × 10¹⁰³(104-digit number)
36135956842615954026…56858425784039167999
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 10 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
UncommonChain length 10

Roughly 1 in 100 blocks. Solid but expected in a healthy network.

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:57,676,226 XPM·at block #6,804,021 · updates every 60s
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