Block #314,085

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/15/2013, 7:12:01 PM · Difficulty 10.0426 · 6,512,800 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
db5b32a6d612d5c98319f0071101005e7996c14a8335854fd02e9aa67a666f6e

Height

#314,085

Difficulty

10.042579

Transactions

20

Size

4.50 KB

Version

2

Bits

0a0ae679

Nonce

25,039

Timestamp

12/15/2013, 7:12:01 PM

Confirmations

6,512,800

Merkle Root

074722717455c4df6f4e66f0ce2eadf3522482e5f24120764e74e924b3b898c8
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.

2.705 × 10¹⁰⁰(101-digit number)
27055585109609514765…31759474312425282561
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
2.705 × 10¹⁰⁰(101-digit number)
27055585109609514765…31759474312425282561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.411 × 10¹⁰⁰(101-digit number)
54111170219219029531…63518948624850565121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.082 × 10¹⁰¹(102-digit number)
10822234043843805906…27037897249701130241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.164 × 10¹⁰¹(102-digit number)
21644468087687611812…54075794499402260481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.328 × 10¹⁰¹(102-digit number)
43288936175375223624…08151588998804520961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
8.657 × 10¹⁰¹(102-digit number)
86577872350750447249…16303177997609041921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.731 × 10¹⁰²(103-digit number)
17315574470150089449…32606355995218083841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.463 × 10¹⁰²(103-digit number)
34631148940300178899…65212711990436167681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.926 × 10¹⁰²(103-digit number)
69262297880600357799…30425423980872335361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.385 × 10¹⁰³(104-digit number)
13852459576120071559…60850847961744670721
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:57,859,245 XPM·at block #6,826,884 · updates every 60s
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