Block #524,990

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/4/2014, 12:21:29 PM · Difficulty 10.8783 · 6,267,545 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
22757713d53ef8ef75b5270d6e5960d12d30ada7b6325baf7e979f7b97e83369

Height

#524,990

Difficulty

10.878333

Transactions

10

Size

2.77 KB

Version

2

Bits

0ae0da73

Nonce

54,708,309

Timestamp

5/4/2014, 12:21:29 PM

Confirmations

6,267,545

Merkle Root

7f2cbc0049e03ff6469e67f8c0be5deb72929fff56755a09bc53dbd6d19d9a67
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.

1.432 × 10⁹⁸(99-digit number)
14320130474067122929…00454384602315064161
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
1.432 × 10⁹⁸(99-digit number)
14320130474067122929…00454384602315064161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.864 × 10⁹⁸(99-digit number)
28640260948134245859…00908769204630128321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.728 × 10⁹⁸(99-digit number)
57280521896268491719…01817538409260256641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.145 × 10⁹⁹(100-digit number)
11456104379253698343…03635076818520513281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.291 × 10⁹⁹(100-digit number)
22912208758507396687…07270153637041026561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.582 × 10⁹⁹(100-digit number)
45824417517014793375…14540307274082053121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
9.164 × 10⁹⁹(100-digit number)
91648835034029586751…29080614548164106241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.832 × 10¹⁰⁰(101-digit number)
18329767006805917350…58161229096328212481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.665 × 10¹⁰⁰(101-digit number)
36659534013611834700…16322458192656424961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
7.331 × 10¹⁰⁰(101-digit number)
73319068027223669401…32644916385312849921
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:57,584,249 XPM·at block #6,792,534 · updates every 60s
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