1. #6,810,8541CC11 primes

    Cunningham 1st · ⛏️ coinsforall.io

Block #434,412

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/8/2014, 6:36:25 AM · Difficulty 10.3441 · 6,376,443 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
f3bbb974f48bc4d45dc2db44a726cfc4d4974324334569ead62f5f7114d52d47

Height

#434,412

Difficulty

10.344086

Transactions

3

Size

2.65 KB

Version

2

Bits

0a5815fe

Nonce

27,772

Timestamp

3/8/2014, 6:36:25 AM

Confirmations

6,376,443

Merkle Root

fe29821d3f4fc226b3bb6ad07d7833d24bae63bd4504c4eee1cbe7dab9018e41
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.

1.739 × 10¹⁰⁰(101-digit number)
17398935885647174143…21264443758347564801
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
1.739 × 10¹⁰⁰(101-digit number)
17398935885647174143…21264443758347564801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.479 × 10¹⁰⁰(101-digit number)
34797871771294348286…42528887516695129601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
6.959 × 10¹⁰⁰(101-digit number)
69595743542588696573…85057775033390259201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.391 × 10¹⁰¹(102-digit number)
13919148708517739314…70115550066780518401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.783 × 10¹⁰¹(102-digit number)
27838297417035478629…40231100133561036801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.567 × 10¹⁰¹(102-digit number)
55676594834070957258…80462200267122073601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.113 × 10¹⁰²(103-digit number)
11135318966814191451…60924400534244147201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.227 × 10¹⁰²(103-digit number)
22270637933628382903…21848801068488294401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.454 × 10¹⁰²(103-digit number)
44541275867256765806…43697602136976588801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
8.908 × 10¹⁰²(103-digit number)
89082551734513531613…87395204273953177601
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:57,730,937 XPM·at block #6,810,854 · updates every 60s
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