Block #313,459

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/15/2013, 11:52:06 AM · Difficulty 10.0066 · 6,482,801 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
6880769e1d66a8224129bec59fdc96a9b9f0605f43da5c0e85efef94fc1054bc

Height

#313,459

Difficulty

10.006591

Transactions

11

Size

6.56 KB

Version

2

Bits

0a01aff1

Nonce

67,731

Timestamp

12/15/2013, 11:52:06 AM

Confirmations

6,482,801

Merkle Root

2151f2005fd83bb83cc101c1a909448b382217162aefe7009e376a6df8eb035d
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.

9.441 × 10⁹⁸(99-digit number)
94412682425231917225…80755776673739891199
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
9.441 × 10⁹⁸(99-digit number)
94412682425231917225…80755776673739891199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.888 × 10⁹⁹(100-digit number)
18882536485046383445…61511553347479782399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.776 × 10⁹⁹(100-digit number)
37765072970092766890…23023106694959564799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
7.553 × 10⁹⁹(100-digit number)
75530145940185533780…46046213389919129599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.510 × 10¹⁰⁰(101-digit number)
15106029188037106756…92092426779838259199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.021 × 10¹⁰⁰(101-digit number)
30212058376074213512…84184853559676518399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.042 × 10¹⁰⁰(101-digit number)
60424116752148427024…68369707119353036799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.208 × 10¹⁰¹(102-digit number)
12084823350429685404…36739414238706073599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.416 × 10¹⁰¹(102-digit number)
24169646700859370809…73478828477412147199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.833 × 10¹⁰¹(102-digit number)
48339293401718741619…46957656954824294399
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 First 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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,614,078 XPM·at block #6,796,259 · updates every 60s
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