Block #344,355

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/5/2014, 6:24:53 AM · Difficulty 10.1919 · 6,454,954 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
6b6e6cd116964ca0f4b13c12605a66bf1c47ed878eff132446b49930816985f5

Height

#344,355

Difficulty

10.191906

Transactions

4

Size

1.88 KB

Version

2

Bits

0a3120c3

Nonce

40,326

Timestamp

1/5/2014, 6:24:53 AM

Confirmations

6,454,954

Merkle Root

d06b1fe1f90d3897d7c0a90e3cb9feeef0dc91499b4ce5a8cb0999306c9d84fc
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.

8.623 × 10⁹¹(92-digit number)
86239395728332081808…51049553039637352001
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
8.623 × 10⁹¹(92-digit number)
86239395728332081808…51049553039637352001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.724 × 10⁹²(93-digit number)
17247879145666416361…02099106079274704001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.449 × 10⁹²(93-digit number)
34495758291332832723…04198212158549408001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.899 × 10⁹²(93-digit number)
68991516582665665446…08396424317098816001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.379 × 10⁹³(94-digit number)
13798303316533133089…16792848634197632001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.759 × 10⁹³(94-digit number)
27596606633066266178…33585697268395264001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.519 × 10⁹³(94-digit number)
55193213266132532357…67171394536790528001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.103 × 10⁹⁴(95-digit number)
11038642653226506471…34342789073581056001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.207 × 10⁹⁴(95-digit number)
22077285306453012942…68685578147162112001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.415 × 10⁹⁴(95-digit number)
44154570612906025885…37371156294324224001
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:57,638,518 XPM·at block #6,799,308 · updates every 60s
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