Block #331,101

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/27/2013, 3:42:46 AM · Difficulty 10.1654 · 6,470,713 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
ff06b0713c112c054fadbd56bff49c31bb94355fd31c8675b18c6cf5b6782f8b

Height

#331,101

Difficulty

10.165375

Transactions

12

Size

4.04 KB

Version

2

Bits

0a2a5606

Nonce

55,295

Timestamp

12/27/2013, 3:42:46 AM

Confirmations

6,470,713

Merkle Root

1d8606c4ed3faf26457a2bc4bee375fa5a27450bd7bcf525a955fcd977cbda4f
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.

4.435 × 10⁹¹(92-digit number)
44354851611505500558…52827337194257230399
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
4.435 × 10⁹¹(92-digit number)
44354851611505500558…52827337194257230399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.870 × 10⁹¹(92-digit number)
88709703223011001117…05654674388514460799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.774 × 10⁹²(93-digit number)
17741940644602200223…11309348777028921599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.548 × 10⁹²(93-digit number)
35483881289204400446…22618697554057843199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
7.096 × 10⁹²(93-digit number)
70967762578408800893…45237395108115686399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.419 × 10⁹³(94-digit number)
14193552515681760178…90474790216231372799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.838 × 10⁹³(94-digit number)
28387105031363520357…80949580432462745599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.677 × 10⁹³(94-digit number)
56774210062727040714…61899160864925491199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.135 × 10⁹⁴(95-digit number)
11354842012545408142…23798321729850982399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.270 × 10⁹⁴(95-digit number)
22709684025090816285…47596643459701964799
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:57,658,604 XPM·at block #6,801,813 · updates every 60s
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