Block #337,898

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/1/2014, 1:02:47 AM · Difficulty 10.1275 · 6,466,154 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
d21599dc3d93ed2eefc0cbdb64693b1f65660342d5bd4f31972227219c84408b

Height

#337,898

Difficulty

10.127543

Transactions

21

Size

9.19 KB

Version

2

Bits

0a20a6a5

Nonce

118,569

Timestamp

1/1/2014, 1:02:47 AM

Confirmations

6,466,154

Merkle Root

c590098aa27decbbbe0664ed31bdb9a13637dcdafa87bbdcb63a6dd786a441e9
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.

1.734 × 10⁹⁷(98-digit number)
17341441275869978830…52000527913480712001
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
1.734 × 10⁹⁷(98-digit number)
17341441275869978830…52000527913480712001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.468 × 10⁹⁷(98-digit number)
34682882551739957660…04001055826961424001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
6.936 × 10⁹⁷(98-digit number)
69365765103479915321…08002111653922848001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.387 × 10⁹⁸(99-digit number)
13873153020695983064…16004223307845696001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.774 × 10⁹⁸(99-digit number)
27746306041391966128…32008446615691392001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.549 × 10⁹⁸(99-digit number)
55492612082783932257…64016893231382784001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.109 × 10⁹⁹(100-digit number)
11098522416556786451…28033786462765568001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.219 × 10⁹⁹(100-digit number)
22197044833113572902…56067572925531136001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.439 × 10⁹⁹(100-digit number)
44394089666227145805…12135145851062272001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
8.878 × 10⁹⁹(100-digit number)
88788179332454291611…24270291702124544001
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:57,676,471 XPM·at block #6,804,051 · updates every 60s
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