Block #364,228

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/17/2014, 10:29:38 PM · Difficulty 10.4206 · 6,438,843 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
4ad249aad734b54b3b52df8ceb0a87cfd262328ce1357f563a96b77fa9efd201

Height

#364,228

Difficulty

10.420579

Transactions

4

Size

1.71 KB

Version

2

Bits

0a6bab10

Nonce

15,319

Timestamp

1/17/2014, 10:29:38 PM

Confirmations

6,438,843

Merkle Root

c63172a28bd536fc8a604bf6d7dc4b4f9f83119ece589d6a05dfedd24f1d781a
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.

2.946 × 10⁹⁹(100-digit number)
29464124342216794071…49280499008627010561
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
2.946 × 10⁹⁹(100-digit number)
29464124342216794071…49280499008627010561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.892 × 10⁹⁹(100-digit number)
58928248684433588143…98560998017254021121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.178 × 10¹⁰⁰(101-digit number)
11785649736886717628…97121996034508042241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.357 × 10¹⁰⁰(101-digit number)
23571299473773435257…94243992069016084481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.714 × 10¹⁰⁰(101-digit number)
47142598947546870514…88487984138032168961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
9.428 × 10¹⁰⁰(101-digit number)
94285197895093741029…76975968276064337921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.885 × 10¹⁰¹(102-digit number)
18857039579018748205…53951936552128675841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.771 × 10¹⁰¹(102-digit number)
37714079158037496411…07903873104257351681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
7.542 × 10¹⁰¹(102-digit number)
75428158316074992823…15807746208514703361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.508 × 10¹⁰²(103-digit number)
15085631663214998564…31615492417029406721
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:57,668,597 XPM·at block #6,803,070 · updates every 60s
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