Block #534,256

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/10/2014, 5:06:52 AM · Difficulty 10.9017 · 6,271,582 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
fe972923df0a6becb38d1bd2621fabed12cb328a389317ebe206b0f7ce9f5de5

Height

#534,256

Difficulty

10.901734

Transactions

9

Size

2.11 KB

Version

2

Bits

0ae6d806

Nonce

31,036,683

Timestamp

5/10/2014, 5:06:52 AM

Confirmations

6,271,582

Merkle Root

449e7b50a4f1f98228c6f5198f0681792cae23285bb10520e710d3ca81e9c567
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.

1.250 × 10¹⁰¹(102-digit number)
12509356128835598747…04322088046539811841
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
1.250 × 10¹⁰¹(102-digit number)
12509356128835598747…04322088046539811841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.501 × 10¹⁰¹(102-digit number)
25018712257671197494…08644176093079623681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.003 × 10¹⁰¹(102-digit number)
50037424515342394989…17288352186159247361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.000 × 10¹⁰²(103-digit number)
10007484903068478997…34576704372318494721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.001 × 10¹⁰²(103-digit number)
20014969806136957995…69153408744636989441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.002 × 10¹⁰²(103-digit number)
40029939612273915991…38306817489273978881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
8.005 × 10¹⁰²(103-digit number)
80059879224547831983…76613634978547957761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.601 × 10¹⁰³(104-digit number)
16011975844909566396…53227269957095915521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.202 × 10¹⁰³(104-digit number)
32023951689819132793…06454539914191831041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
6.404 × 10¹⁰³(104-digit number)
64047903379638265586…12909079828383662081
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:57,690,782 XPM·at block #6,805,837 · updates every 60s
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