Block #115,996

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 8/14/2013, 3:41:22 AM · Difficulty 9.7456 · 6,675,619 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
4f6b6f6fe8855bd0e076e7289ae867286b327269a821ce8a453578d1e567329b

Height

#115,996

Difficulty

9.745562

Transactions

3

Size

813 B

Version

2

Bits

09bedd21

Nonce

264,973

Timestamp

8/14/2013, 3:41:22 AM

Confirmations

6,675,619

Merkle Root

1a507ab3c6ae955e0f6c3d348af0e6544409cb9923a64b3d31d843eef82452b4
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.

1.119 × 10⁹⁸(99-digit number)
11194873124363492269…24090246587629816999
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
1.119 × 10⁹⁸(99-digit number)
11194873124363492269…24090246587629816999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.238 × 10⁹⁸(99-digit number)
22389746248726984539…48180493175259633999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.477 × 10⁹⁸(99-digit number)
44779492497453969079…96360986350519267999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.955 × 10⁹⁸(99-digit number)
89558984994907938159…92721972701038535999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.791 × 10⁹⁹(100-digit number)
17911796998981587631…85443945402077071999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.582 × 10⁹⁹(100-digit number)
35823593997963175263…70887890804154143999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
7.164 × 10⁹⁹(100-digit number)
71647187995926350527…41775781608308287999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.432 × 10¹⁰⁰(101-digit number)
14329437599185270105…83551563216616575999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.865 × 10¹⁰⁰(101-digit number)
28658875198370540211…67103126433233151999
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,576,867 XPM·at block #6,791,614 · updates every 60s
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