Block #479,194

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/7/2014, 1:18:59 PM · Difficulty 10.5023 · 6,330,738 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
1ffcbdaea117b39f14064d88309ac6683b725aa1d58c6b15ee85de8f0cfc5f76

Height

#479,194

Difficulty

10.502336

Transactions

6

Size

13.83 KB

Version

2

Bits

0a809911

Nonce

17,821

Timestamp

4/7/2014, 1:18:59 PM

Confirmations

6,330,738

Merkle Root

d5caccc1471f2c5747e89fc678c9c47cdacc8f321b3d0dc37272aa4c527ec8d9
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.

4.151 × 10⁸⁹(90-digit number)
41515776097734990321…52866029721228815909
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
4.151 × 10⁸⁹(90-digit number)
41515776097734990321…52866029721228815909
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.303 × 10⁸⁹(90-digit number)
83031552195469980643…05732059442457631819
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.660 × 10⁹⁰(91-digit number)
16606310439093996128…11464118884915263639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.321 × 10⁹⁰(91-digit number)
33212620878187992257…22928237769830527279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.642 × 10⁹⁰(91-digit number)
66425241756375984514…45856475539661054559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.328 × 10⁹¹(92-digit number)
13285048351275196902…91712951079322109119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.657 × 10⁹¹(92-digit number)
26570096702550393805…83425902158644218239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.314 × 10⁹¹(92-digit number)
53140193405100787611…66851804317288436479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.062 × 10⁹²(93-digit number)
10628038681020157522…33703608634576872959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.125 × 10⁹²(93-digit number)
21256077362040315044…67407217269153745919
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:57,723,543 XPM·at block #6,809,931 · updates every 60s
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