Block #322,495

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/21/2013, 1:25:19 AM · Difficulty 10.1923 · 6,494,101 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
e2e6551f7c59453fc367b8e28e9d99ff3d556d4eb5c71c92c54b66e7b91d074b

Height

#322,495

Difficulty

10.192256

Transactions

10

Size

4.02 KB

Version

2

Bits

0a3137a9

Nonce

37,787

Timestamp

12/21/2013, 1:25:19 AM

Confirmations

6,494,101

Merkle Root

4cc87a9a0966fb130b48b0d568fb9a1574dd2dfb07b0684d7a054f4118e277c6
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.

3.960 × 10⁹⁹(100-digit number)
39608667382256407696…25097758251534700799
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
3.960 × 10⁹⁹(100-digit number)
39608667382256407696…25097758251534700799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
7.921 × 10⁹⁹(100-digit number)
79217334764512815393…50195516503069401599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.584 × 10¹⁰⁰(101-digit number)
15843466952902563078…00391033006138803199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.168 × 10¹⁰⁰(101-digit number)
31686933905805126157…00782066012277606399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.337 × 10¹⁰⁰(101-digit number)
63373867811610252314…01564132024555212799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.267 × 10¹⁰¹(102-digit number)
12674773562322050462…03128264049110425599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.534 × 10¹⁰¹(102-digit number)
25349547124644100925…06256528098220851199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.069 × 10¹⁰¹(102-digit number)
50699094249288201851…12513056196441702399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.013 × 10¹⁰²(103-digit number)
10139818849857640370…25026112392883404799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.027 × 10¹⁰²(103-digit number)
20279637699715280740…50052224785766809599
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:57,776,893 XPM·at block #6,816,595 · updates every 60s
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