Block #344,705

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/5/2014, 11:21:05 AM · Difficulty 10.2004 · 6,450,348 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
9d596513dfe880ceb65a7c6c467d668ccaa99fb607842d02278a9b8855bc80cd

Height

#344,705

Difficulty

10.200380

Transactions

9

Size

2.25 KB

Version

2

Bits

0a334c16

Nonce

43,509

Timestamp

1/5/2014, 11:21:05 AM

Confirmations

6,450,348

Merkle Root

6c322dabb9e1aa3b117d88847f4493b6f6442ba660756dd2d83562e8fc5d74a1
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.

1.494 × 10¹⁰¹(102-digit number)
14946345469309850851…59802513460550744961
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
1.494 × 10¹⁰¹(102-digit number)
14946345469309850851…59802513460550744961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.989 × 10¹⁰¹(102-digit number)
29892690938619701703…19605026921101489921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.978 × 10¹⁰¹(102-digit number)
59785381877239403407…39210053842202979841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.195 × 10¹⁰²(103-digit number)
11957076375447880681…78420107684405959681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.391 × 10¹⁰²(103-digit number)
23914152750895761363…56840215368811919361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.782 × 10¹⁰²(103-digit number)
47828305501791522726…13680430737623838721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
9.565 × 10¹⁰²(103-digit number)
95656611003583045452…27360861475247677441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.913 × 10¹⁰³(104-digit number)
19131322200716609090…54721722950495354881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.826 × 10¹⁰³(104-digit number)
38262644401433218181…09443445900990709761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
7.652 × 10¹⁰³(104-digit number)
76525288802866436362…18886891801981419521
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:57,604,464 XPM·at block #6,795,052 · updates every 60s
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