Block #3,285,624

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 7/28/2019, 8:25:44 PM · Difficulty 10.9948 · 3,520,487 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
d7ea923cf4e0ea8f13092b37d6c61f8f4bde3cf2e5a3f5a7053703e7035599ca

Height

#3,285,624

Difficulty

10.994773

Transactions

6

Size

2.01 KB

Version

2

Bits

0afea96e

Nonce

194,089,307

Timestamp

7/28/2019, 8:25:44 PM

Confirmations

3,520,487

Merkle Root

4aad3fea973008ae5f219511bbb25113616e2cb4fc70dd4e827bad1f8ac10a85
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.

2.043 × 10⁹⁷(98-digit number)
20430917011445154957…40157389396168191999
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
2.043 × 10⁹⁷(98-digit number)
20430917011445154957…40157389396168191999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.086 × 10⁹⁷(98-digit number)
40861834022890309915…80314778792336383999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.172 × 10⁹⁷(98-digit number)
81723668045780619831…60629557584672767999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.634 × 10⁹⁸(99-digit number)
16344733609156123966…21259115169345535999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.268 × 10⁹⁸(99-digit number)
32689467218312247932…42518230338691071999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.537 × 10⁹⁸(99-digit number)
65378934436624495865…85036460677382143999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.307 × 10⁹⁹(100-digit number)
13075786887324899173…70072921354764287999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.615 × 10⁹⁹(100-digit number)
26151573774649798346…40145842709528575999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.230 × 10⁹⁹(100-digit number)
52303147549299596692…80291685419057151999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.046 × 10¹⁰⁰(101-digit number)
10460629509859919338…60583370838114303999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
2.092 × 10¹⁰⁰(101-digit number)
20921259019719838676…21166741676228607999
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,692,962 XPM·at block #6,806,110 · updates every 60s
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