1. #6,816,7121CC10 primes

    Cunningham 1st · ⛏️ coinsforall.io

  2. #6,816,711TWN11 primes

    Bi-Twin · ⛏️ coinsforall.io

Block #318,270

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/18/2013, 6:04:58 AM · Difficulty 10.1598 · 6,498,443 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
dcc4b37a090daa2ce56ccd400851c2eb8d8a3051f18191d4b617c58c847ee5e5

Height

#318,270

Difficulty

10.159808

Transactions

14

Size

3.93 KB

Version

2

Bits

0a28e92f

Nonce

92,250

Timestamp

12/18/2013, 6:04:58 AM

Confirmations

6,498,443

Merkle Root

b9546a1351cf93fae3af2ed2e4c7f6ccfbbab9978a13d450a6b69179a54cee0c
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.

4.682 × 10⁹⁷(98-digit number)
46826888201048699748…86653288235815399279
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
4.682 × 10⁹⁷(98-digit number)
46826888201048699748…86653288235815399279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
9.365 × 10⁹⁷(98-digit number)
93653776402097399496…73306576471630798559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.873 × 10⁹⁸(99-digit number)
18730755280419479899…46613152943261597119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.746 × 10⁹⁸(99-digit number)
37461510560838959798…93226305886523194239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
7.492 × 10⁹⁸(99-digit number)
74923021121677919597…86452611773046388479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.498 × 10⁹⁹(100-digit number)
14984604224335583919…72905223546092776959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.996 × 10⁹⁹(100-digit number)
29969208448671167838…45810447092185553919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.993 × 10⁹⁹(100-digit number)
59938416897342335677…91620894184371107839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.198 × 10¹⁰⁰(101-digit number)
11987683379468467135…83241788368742215679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.397 × 10¹⁰⁰(101-digit number)
23975366758936934271…66483576737484431359
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:57,777,828 XPM·at block #6,816,712 · updates every 60s
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