Block #532,019

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/8/2014, 8:35:36 PM · Difficulty 10.8960 · 6,264,377 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
3dafc0c39528a9918095f35f284da6ffc2afb5cecb2d3ec20fd48feac5e5b661

Height

#532,019

Difficulty

10.895953

Transactions

9

Size

3.26 KB

Version

2

Bits

0ae55d2b

Nonce

174,194,578

Timestamp

5/8/2014, 8:35:36 PM

Confirmations

6,264,377

Merkle Root

322033e0fc66ded0bf0c0768c8d618108e48216a74bf97318ba9d212ac4562dd
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.

1.305 × 10⁹⁸(99-digit number)
13056193317834849578…45863091425225056001
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
1.305 × 10⁹⁸(99-digit number)
13056193317834849578…45863091425225056001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.611 × 10⁹⁸(99-digit number)
26112386635669699157…91726182850450112001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.222 × 10⁹⁸(99-digit number)
52224773271339398314…83452365700900224001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.044 × 10⁹⁹(100-digit number)
10444954654267879662…66904731401800448001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.088 × 10⁹⁹(100-digit number)
20889909308535759325…33809462803600896001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.177 × 10⁹⁹(100-digit number)
41779818617071518651…67618925607201792001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
8.355 × 10⁹⁹(100-digit number)
83559637234143037302…35237851214403584001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.671 × 10¹⁰⁰(101-digit number)
16711927446828607460…70475702428807168001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.342 × 10¹⁰⁰(101-digit number)
33423854893657214921…40951404857614336001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
6.684 × 10¹⁰⁰(101-digit number)
66847709787314429842…81902809715228672001
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 Second 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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,615,165 XPM·at block #6,796,395 · updates every 60s
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