Block #499,807

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/18/2014, 7:12:34 PM · Difficulty 10.7956 · 6,297,034 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
fafb235d560c0605c5136b69073a2ddc9e0519082aee16cb8cb31f9dda4f2a50

Height

#499,807

Difficulty

10.795567

Transactions

2

Size

4.44 KB

Version

2

Bits

0acbaa4a

Nonce

40,667,065

Timestamp

4/18/2014, 7:12:34 PM

Confirmations

6,297,034

Merkle Root

78122d55b93eda904f25ccfb77b0d559ee560a82ff39651a94b2a0ac50a442a4
Transactions (2)
1 in → 1 out8.6200 XPM116 B
29 in → 1 out87.3896 XPM4.24 KB
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.

2.868 × 10⁹⁸(99-digit number)
28682741157821511549…48779112769930185599
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
2.868 × 10⁹⁸(99-digit number)
28682741157821511549…48779112769930185599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
5.736 × 10⁹⁸(99-digit number)
57365482315643023098…97558225539860371199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.147 × 10⁹⁹(100-digit number)
11473096463128604619…95116451079720742399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.294 × 10⁹⁹(100-digit number)
22946192926257209239…90232902159441484799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.589 × 10⁹⁹(100-digit number)
45892385852514418479…80465804318882969599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
9.178 × 10⁹⁹(100-digit number)
91784771705028836958…60931608637765939199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.835 × 10¹⁰⁰(101-digit number)
18356954341005767391…21863217275531878399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.671 × 10¹⁰⁰(101-digit number)
36713908682011534783…43726434551063756799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
7.342 × 10¹⁰⁰(101-digit number)
73427817364023069566…87452869102127513599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.468 × 10¹⁰¹(102-digit number)
14685563472804613913…74905738204255027199
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:57,618,740 XPM·at block #6,796,840 · updates every 60s
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