Block #453,627

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/21/2014, 10:34:58 AM · Difficulty 10.3863 · 6,342,755 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
b2b557591668278c2fbd469ab23818fca3993ee6a7e2754a8f6680e97b423bb7

Height

#453,627

Difficulty

10.386326

Transactions

3

Size

810 B

Version

2

Bits

0a62e63f

Nonce

109,347

Timestamp

3/21/2014, 10:34:58 AM

Confirmations

6,342,755

Merkle Root

64f72c31f295e2f01a5b6798c07792a1dfdaa0deb48a3428c97c87779dbfc549
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.

3.741 × 10¹⁰³(104-digit number)
37413220233491241408…03584569429337681921
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
3.741 × 10¹⁰³(104-digit number)
37413220233491241408…03584569429337681921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
7.482 × 10¹⁰³(104-digit number)
74826440466982482817…07169138858675363841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.496 × 10¹⁰⁴(105-digit number)
14965288093396496563…14338277717350727681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.993 × 10¹⁰⁴(105-digit number)
29930576186792993127…28676555434701455361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.986 × 10¹⁰⁴(105-digit number)
59861152373585986254…57353110869402910721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.197 × 10¹⁰⁵(106-digit number)
11972230474717197250…14706221738805821441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.394 × 10¹⁰⁵(106-digit number)
23944460949434394501…29412443477611642881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.788 × 10¹⁰⁵(106-digit number)
47888921898868789003…58824886955223285761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
9.577 × 10¹⁰⁵(106-digit number)
95777843797737578006…17649773910446571521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.915 × 10¹⁰⁶(107-digit number)
19155568759547515601…35299547820893143041
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:57,615,053 XPM·at block #6,796,381 · updates every 60s
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