Block #1,004,227

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/6/2015, 5:33:26 AM · Difficulty 10.7455 · 5,799,401 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
2c7c54e46687b10b340b56df7a86a9832029ec36cdd269892e1c83e23d2da24f

Height

#1,004,227

Difficulty

10.745491

Transactions

9

Size

10.49 KB

Version

2

Bits

0abed87e

Nonce

834,422,972

Timestamp

4/6/2015, 5:33:26 AM

Confirmations

5,799,401

Merkle Root

baccd3bdab7ae6d4d65b045ac8aff3955833334601ebf1deff71b63ce03cc05c
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.

3.516 × 10⁹⁷(98-digit number)
35162490334760736223…61843460907424511999
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
3.516 × 10⁹⁷(98-digit number)
35162490334760736223…61843460907424511999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
7.032 × 10⁹⁷(98-digit number)
70324980669521472447…23686921814849023999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.406 × 10⁹⁸(99-digit number)
14064996133904294489…47373843629698047999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.812 × 10⁹⁸(99-digit number)
28129992267808588978…94747687259396095999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.625 × 10⁹⁸(99-digit number)
56259984535617177957…89495374518792191999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.125 × 10⁹⁹(100-digit number)
11251996907123435591…78990749037584383999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.250 × 10⁹⁹(100-digit number)
22503993814246871183…57981498075168767999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.500 × 10⁹⁹(100-digit number)
45007987628493742366…15962996150337535999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
9.001 × 10⁹⁹(100-digit number)
90015975256987484732…31925992300675071999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.800 × 10¹⁰⁰(101-digit number)
18003195051397496946…63851984601350143999
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:57,673,056 XPM·at block #6,803,627 · updates every 60s
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