Block #116,310

2CCLength 9★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 8/14/2013, 8:14:12 AM · Difficulty 9.7475 · 6,700,762 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
49f32a9e3210482465f9bb7de23341edbd11e33459d40dcfe13370d4a0f64c54

Height

#116,310

Difficulty

9.747503

Transactions

3

Size

1.07 KB

Version

2

Bits

09bf5c59

Nonce

86,546

Timestamp

8/14/2013, 8:14:12 AM

Confirmations

6,700,762

Merkle Root

a741565094bb94d3851ef30a92789a273caee1d61670d63c32a62c7eab6d9788
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.

8.427 × 10⁹⁹(100-digit number)
84274323306100255779…54794947079950322721
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
8.427 × 10⁹⁹(100-digit number)
84274323306100255779…54794947079950322721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.685 × 10¹⁰⁰(101-digit number)
16854864661220051155…09589894159900645441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.370 × 10¹⁰⁰(101-digit number)
33709729322440102311…19179788319801290881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.741 × 10¹⁰⁰(101-digit number)
67419458644880204623…38359576639602581761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.348 × 10¹⁰¹(102-digit number)
13483891728976040924…76719153279205163521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.696 × 10¹⁰¹(102-digit number)
26967783457952081849…53438306558410327041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.393 × 10¹⁰¹(102-digit number)
53935566915904163698…06876613116820654081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.078 × 10¹⁰²(103-digit number)
10787113383180832739…13753226233641308161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.157 × 10¹⁰²(103-digit number)
21574226766361665479…27506452467282616321
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 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
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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,780,612 XPM·at block #6,817,071 · updates every 60s
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