1. #6,793,566TWN10 primes

    Bi-Twin · ⛏️ coinsforall.io

Block #522,437

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/3/2014, 1:05:32 AM · Difficulty 10.8671 · 6,271,130 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
7ae9e3bb4a50694f0b5da948bfcd977096600a188fc80254adcbc6134aa6dd48

Height

#522,437

Difficulty

10.867106

Transactions

10

Size

2.15 KB

Version

2

Bits

0addfab0

Nonce

5,113,492

Timestamp

5/3/2014, 1:05:32 AM

Confirmations

6,271,130

Merkle Root

95659c7c8ae94208265fd9b958a54edbdb139933b63120558c59239196b9f4b1
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.

2.412 × 10⁹⁶(97-digit number)
24126888648047088004…07993320435804423041
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
2.412 × 10⁹⁶(97-digit number)
24126888648047088004…07993320435804423041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
4.825 × 10⁹⁶(97-digit number)
48253777296094176008…15986640871608846081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
9.650 × 10⁹⁶(97-digit number)
96507554592188352016…31973281743217692161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.930 × 10⁹⁷(98-digit number)
19301510918437670403…63946563486435384321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.860 × 10⁹⁷(98-digit number)
38603021836875340806…27893126972870768641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
7.720 × 10⁹⁷(98-digit number)
77206043673750681613…55786253945741537281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.544 × 10⁹⁸(99-digit number)
15441208734750136322…11572507891483074561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.088 × 10⁹⁸(99-digit number)
30882417469500272645…23145015782966149121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.176 × 10⁹⁸(99-digit number)
61764834939000545290…46290031565932298241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.235 × 10⁹⁹(100-digit number)
12352966987800109058…92580063131864596481
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:57,592,531 XPM·at block #6,793,566 · updates every 60s
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