Block #361,510

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/16/2014, 3:16:24 AM · Difficulty 10.4046 · 6,444,356 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
a25e44738a510869387c66a962bdd389295aedbdf788313f7c054f03260bcbce

Height

#361,510

Difficulty

10.404631

Transactions

2

Size

1.27 KB

Version

2

Bits

0a6795ea

Nonce

64,670

Timestamp

1/16/2014, 3:16:24 AM

Confirmations

6,444,356

Merkle Root

524b1ecc8e963edabf53cbf0fef21a3a3ef536e6c0af4ff116a6159fe9055d76
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.

4.582 × 10¹⁰⁵(106-digit number)
45828323119520126391…60279039625540204001
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
4.582 × 10¹⁰⁵(106-digit number)
45828323119520126391…60279039625540204001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.165 × 10¹⁰⁵(106-digit number)
91656646239040252782…20558079251080408001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.833 × 10¹⁰⁶(107-digit number)
18331329247808050556…41116158502160816001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.666 × 10¹⁰⁶(107-digit number)
36662658495616101112…82232317004321632001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.332 × 10¹⁰⁶(107-digit number)
73325316991232202225…64464634008643264001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.466 × 10¹⁰⁷(108-digit number)
14665063398246440445…28929268017286528001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.933 × 10¹⁰⁷(108-digit number)
29330126796492880890…57858536034573056001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.866 × 10¹⁰⁷(108-digit number)
58660253592985761780…15717072069146112001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.173 × 10¹⁰⁸(109-digit number)
11732050718597152356…31434144138292224001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.346 × 10¹⁰⁸(109-digit number)
23464101437194304712…62868288276584448001
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:57,691,011 XPM·at block #6,805,865 · updates every 60s
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