Block #429,945

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/5/2014, 4:28:04 AM · Difficulty 10.3397 · 6,362,749 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
3f81dd4beaaf230d9eebac657a2b288762622ade4fd1b9766fadba476aabbc1b

Height

#429,945

Difficulty

10.339734

Transactions

3

Size

4.62 KB

Version

2

Bits

0a56f8cb

Nonce

174,196

Timestamp

3/5/2014, 4:28:04 AM

Confirmations

6,362,749

Merkle Root

acc943a9986c0139394b833fc1a606be87253b05537af2a656f26fcdd13b4f82
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.

2.044 × 10⁹²(93-digit number)
20449457725365913427…96190286064662207999
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
2.044 × 10⁹²(93-digit number)
20449457725365913427…96190286064662207999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.089 × 10⁹²(93-digit number)
40898915450731826855…92380572129324415999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.179 × 10⁹²(93-digit number)
81797830901463653711…84761144258648831999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.635 × 10⁹³(94-digit number)
16359566180292730742…69522288517297663999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.271 × 10⁹³(94-digit number)
32719132360585461484…39044577034595327999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.543 × 10⁹³(94-digit number)
65438264721170922969…78089154069190655999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.308 × 10⁹⁴(95-digit number)
13087652944234184593…56178308138381311999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.617 × 10⁹⁴(95-digit number)
26175305888468369187…12356616276762623999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.235 × 10⁹⁴(95-digit number)
52350611776936738375…24713232553525247999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.047 × 10⁹⁵(96-digit number)
10470122355387347675…49426465107050495999
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:57,585,527 XPM·at block #6,792,693 · updates every 60s
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