Block #445,922

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/16/2014, 5:30:56 AM · Difficulty 10.3590 · 6,366,556 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
810993a44b88fd8232cd59e3834600ca6d5c1b4afa3ba9d8b9b238b6f1d58731

Height

#445,922

Difficulty

10.359025

Transactions

1

Size

900 B

Version

2

Bits

0a5be918

Nonce

74,667

Timestamp

3/16/2014, 5:30:56 AM

Confirmations

6,366,556

Merkle Root

abe67c69cd9b620772ea20211a7b79564dfa1a0efa63a6d9904f8a85c0ce6a4a
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.

7.819 × 10⁹²(93-digit number)
78194956321672569825…42962481384902164481
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
7.819 × 10⁹²(93-digit number)
78194956321672569825…42962481384902164481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.563 × 10⁹³(94-digit number)
15638991264334513965…85924962769804328961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.127 × 10⁹³(94-digit number)
31277982528669027930…71849925539608657921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.255 × 10⁹³(94-digit number)
62555965057338055860…43699851079217315841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.251 × 10⁹⁴(95-digit number)
12511193011467611172…87399702158434631681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.502 × 10⁹⁴(95-digit number)
25022386022935222344…74799404316869263361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.004 × 10⁹⁴(95-digit number)
50044772045870444688…49598808633738526721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.000 × 10⁹⁵(96-digit number)
10008954409174088937…99197617267477053441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.001 × 10⁹⁵(96-digit number)
20017908818348177875…98395234534954106881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.003 × 10⁹⁵(96-digit number)
40035817636696355750…96790469069908213761
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:57,743,852 XPM·at block #6,812,477 · updates every 60s
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