Block #432,745

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/7/2014, 3:17:46 AM · Difficulty 10.3395 · 6,362,282 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
9b136439f3b04e862a88b6dba1d7a1940a579c400470c2e7607a3a06b3da052d

Height

#432,745

Difficulty

10.339457

Transactions

6

Size

5.87 KB

Version

2

Bits

0a56e6ab

Nonce

90,496

Timestamp

3/7/2014, 3:17:46 AM

Confirmations

6,362,282

Merkle Root

82a87d6d46930997ea62fb5fde05ca74d38fe45fb049f82b30bbb6532af6a0f6
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.

1.379 × 10¹⁰⁰(101-digit number)
13798152775222811197…86224634142603174401
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
1.379 × 10¹⁰⁰(101-digit number)
13798152775222811197…86224634142603174401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.759 × 10¹⁰⁰(101-digit number)
27596305550445622394…72449268285206348801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.519 × 10¹⁰⁰(101-digit number)
55192611100891244789…44898536570412697601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.103 × 10¹⁰¹(102-digit number)
11038522220178248957…89797073140825395201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.207 × 10¹⁰¹(102-digit number)
22077044440356497915…79594146281650790401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.415 × 10¹⁰¹(102-digit number)
44154088880712995831…59188292563301580801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
8.830 × 10¹⁰¹(102-digit number)
88308177761425991662…18376585126603161601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.766 × 10¹⁰²(103-digit number)
17661635552285198332…36753170253206323201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.532 × 10¹⁰²(103-digit number)
35323271104570396665…73506340506412646401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
7.064 × 10¹⁰²(103-digit number)
70646542209140793330…47012681012825292801
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:57,604,263 XPM·at block #6,795,026 · updates every 60s
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