Block #337,363

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/31/2013, 3:14:50 PM · Difficulty 10.1362 · 6,455,318 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
bd17d1d721ac75120103be1795e63d19e4831e77accc52a72ed54084bfbf4f8d

Height

#337,363

Difficulty

10.136174

Transactions

11

Size

5.29 KB

Version

2

Bits

0a22dc4d

Nonce

11,803

Timestamp

12/31/2013, 3:14:50 PM

Confirmations

6,455,318

Merkle Root

d1b6a8889c6fe4a9ef348c86855e73b3096969efddddf37f8d52569ca6c929cc
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.

1.285 × 10⁹⁸(99-digit number)
12856767722848251006…33878802370355135999
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
1.285 × 10⁹⁸(99-digit number)
12856767722848251006…33878802370355135999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.571 × 10⁹⁸(99-digit number)
25713535445696502013…67757604740710271999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.142 × 10⁹⁸(99-digit number)
51427070891393004027…35515209481420543999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.028 × 10⁹⁹(100-digit number)
10285414178278600805…71030418962841087999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.057 × 10⁹⁹(100-digit number)
20570828356557201611…42060837925682175999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.114 × 10⁹⁹(100-digit number)
41141656713114403222…84121675851364351999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
8.228 × 10⁹⁹(100-digit number)
82283313426228806444…68243351702728703999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.645 × 10¹⁰⁰(101-digit number)
16456662685245761288…36486703405457407999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.291 × 10¹⁰⁰(101-digit number)
32913325370491522577…72973406810914815999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
6.582 × 10¹⁰⁰(101-digit number)
65826650740983045155…45946813621829631999
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:57,585,421 XPM·at block #6,792,680 · updates every 60s
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