Block #337,182

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/31/2013, 12:00:48 PM · Difficulty 10.1386 · 6,472,107 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
4ed36c584cdbe731b415a61a074bb3c6d8a441ad08d56cd8cdb9be08c2561096

Height

#337,182

Difficulty

10.138605

Transactions

1

Size

1.01 KB

Version

2

Bits

0a237ba1

Nonce

7,723

Timestamp

12/31/2013, 12:00:48 PM

Confirmations

6,472,107

Merkle Root

31cf14ccf36c83db85c14f280ca7d052255357b696625f7599ba4215980dc976
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.

2.971 × 10⁹⁵(96-digit number)
29712882474756967327…99156936007491182081
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
2.971 × 10⁹⁵(96-digit number)
29712882474756967327…99156936007491182081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.942 × 10⁹⁵(96-digit number)
59425764949513934654…98313872014982364161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.188 × 10⁹⁶(97-digit number)
11885152989902786930…96627744029964728321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.377 × 10⁹⁶(97-digit number)
23770305979805573861…93255488059929456641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.754 × 10⁹⁶(97-digit number)
47540611959611147723…86510976119858913281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
9.508 × 10⁹⁶(97-digit number)
95081223919222295447…73021952239717826561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.901 × 10⁹⁷(98-digit number)
19016244783844459089…46043904479435653121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.803 × 10⁹⁷(98-digit number)
38032489567688918178…92087808958871306241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
7.606 × 10⁹⁷(98-digit number)
76064979135377836357…84175617917742612481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.521 × 10⁹⁸(99-digit number)
15212995827075567271…68351235835485224961
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:57,718,381 XPM·at block #6,809,288 · updates every 60s
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