Block #341,047

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/3/2014, 5:16:39 AM · Difficulty 10.1315 · 6,455,296 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
275cfa6265819c4e05899aed97073240177e188c479c17b830d219a33492dea7

Height

#341,047

Difficulty

10.131487

Transactions

8

Size

41.74 KB

Version

2

Bits

0a21a926

Nonce

20,459

Timestamp

1/3/2014, 5:16:39 AM

Confirmations

6,455,296

Merkle Root

2c89a1bd018fd87e95fc792c4c34c30b1a91403c4a7d8779a0cb154bf972fb8f
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.

1.146 × 10⁹²(93-digit number)
11464741884170958078…54271258765564316161
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
1.146 × 10⁹²(93-digit number)
11464741884170958078…54271258765564316161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.292 × 10⁹²(93-digit number)
22929483768341916156…08542517531128632321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.585 × 10⁹²(93-digit number)
45858967536683832312…17085035062257264641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
9.171 × 10⁹²(93-digit number)
91717935073367664625…34170070124514529281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.834 × 10⁹³(94-digit number)
18343587014673532925…68340140249029058561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.668 × 10⁹³(94-digit number)
36687174029347065850…36680280498058117121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.337 × 10⁹³(94-digit number)
73374348058694131700…73360560996116234241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.467 × 10⁹⁴(95-digit number)
14674869611738826340…46721121992232468481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.934 × 10⁹⁴(95-digit number)
29349739223477652680…93442243984464936961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.869 × 10⁹⁴(95-digit number)
58699478446955305360…86884487968929873921
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:57,614,736 XPM·at block #6,796,342 · updates every 60s
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