Block #501,984

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/20/2014, 3:17:55 AM · Difficulty 10.8060 · 6,290,810 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
15c15b37fba2bf21faec6fb92167249d0f4732641f2f4b1f292f76821d66b426

Height

#501,984

Difficulty

10.805964

Transactions

2

Size

47.14 KB

Version

2

Bits

0ace53a8

Nonce

83,915

Timestamp

4/20/2014, 3:17:55 AM

Confirmations

6,290,810

Merkle Root

659e48afbec83b4eb55f180b7e568d39ea96f479f9454497ebc5318aa44ad979
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.

6.094 × 10⁸⁹(90-digit number)
60943527861990858860…17524589646829328979
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
6.094 × 10⁸⁹(90-digit number)
60943527861990858860…17524589646829328979
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.218 × 10⁹⁰(91-digit number)
12188705572398171772…35049179293658657959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.437 × 10⁹⁰(91-digit number)
24377411144796343544…70098358587317315919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.875 × 10⁹⁰(91-digit number)
48754822289592687088…40196717174634631839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
9.750 × 10⁹⁰(91-digit number)
97509644579185374176…80393434349269263679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.950 × 10⁹¹(92-digit number)
19501928915837074835…60786868698538527359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.900 × 10⁹¹(92-digit number)
39003857831674149670…21573737397077054719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
7.800 × 10⁹¹(92-digit number)
78007715663348299340…43147474794154109439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.560 × 10⁹²(93-digit number)
15601543132669659868…86294949588308218879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.120 × 10⁹²(93-digit number)
31203086265339319736…72589899176616437759
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:57,586,335 XPM·at block #6,792,793 · updates every 60s
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