Block #324,778

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/22/2013, 1:52:18 PM · Difficulty 10.2073 · 6,477,454 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
344223ce94b91796867f4dc31bdda43fe141b72c02afbeb6952e9d7afc460921

Height

#324,778

Difficulty

10.207279

Transactions

6

Size

1.41 KB

Version

2

Bits

0a351037

Nonce

61,025

Timestamp

12/22/2013, 1:52:18 PM

Confirmations

6,477,454

Merkle Root

bdc2b443154c8e7ec759d9ffc39c3eba3d4be00615e2b61eafb9af5e01e22090
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.

1.358 × 10⁹⁷(98-digit number)
13585367885296041436…17202476320842513759
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
1.358 × 10⁹⁷(98-digit number)
13585367885296041436…17202476320842513759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.717 × 10⁹⁷(98-digit number)
27170735770592082873…34404952641685027519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.434 × 10⁹⁷(98-digit number)
54341471541184165747…68809905283370055039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.086 × 10⁹⁸(99-digit number)
10868294308236833149…37619810566740110079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.173 × 10⁹⁸(99-digit number)
21736588616473666298…75239621133480220159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.347 × 10⁹⁸(99-digit number)
43473177232947332597…50479242266960440319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
8.694 × 10⁹⁸(99-digit number)
86946354465894665195…00958484533920880639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.738 × 10⁹⁹(100-digit number)
17389270893178933039…01916969067841761279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.477 × 10⁹⁹(100-digit number)
34778541786357866078…03833938135683522559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
6.955 × 10⁹⁹(100-digit number)
69557083572715732156…07667876271367045119
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:57,661,864 XPM·at block #6,802,231 · updates every 60s
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