Block #314,511

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/16/2013, 12:14:50 AM · Difficulty 10.0657 · 6,487,995 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
7eee374838da3ed1c8844fcb738802c9e51c3badc0b2775515c37c2c31bc8b91

Height

#314,511

Difficulty

10.065711

Transactions

3

Size

2.81 KB

Version

2

Bits

0a10d275

Nonce

245,750

Timestamp

12/16/2013, 12:14:50 AM

Confirmations

6,487,995

Merkle Root

b68f237ac4980d00ccab428390515e7d4d52e77ae19c97bd87c28f553433afd5
Transactions (3)
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.

5.969 × 10¹⁰⁰(101-digit number)
59693768396984561521…08489252056270008321
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
5.969 × 10¹⁰⁰(101-digit number)
59693768396984561521…08489252056270008321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.193 × 10¹⁰¹(102-digit number)
11938753679396912304…16978504112540016641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.387 × 10¹⁰¹(102-digit number)
23877507358793824608…33957008225080033281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.775 × 10¹⁰¹(102-digit number)
47755014717587649217…67914016450160066561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
9.551 × 10¹⁰¹(102-digit number)
95510029435175298434…35828032900320133121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.910 × 10¹⁰²(103-digit number)
19102005887035059686…71656065800640266241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.820 × 10¹⁰²(103-digit number)
38204011774070119373…43312131601280532481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
7.640 × 10¹⁰²(103-digit number)
76408023548140238747…86624263202561064961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.528 × 10¹⁰³(104-digit number)
15281604709628047749…73248526405122129921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.056 × 10¹⁰³(104-digit number)
30563209419256095498…46497052810244259841
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:57,664,055 XPM·at block #6,802,505 · updates every 60s
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