Block #344,965

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/5/2014, 3:12:58 PM · Difficulty 10.2052 · 6,450,460 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
654260346658b5330a0d139415e39c7566f928bae4282c5860e99e420ed7c7b1

Height

#344,965

Difficulty

10.205151

Transactions

3

Size

42.97 KB

Version

2

Bits

0a3484ce

Nonce

239,413

Timestamp

1/5/2014, 3:12:58 PM

Confirmations

6,450,460

Merkle Root

5e7f8442297a01fc1baf039fed5fef214b7a40cbb77d1a1309444860f0635e8a
Transactions (3)
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.

3.152 × 10⁹⁵(96-digit number)
31523586234912277151…75569548598454575921
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
3.152 × 10⁹⁵(96-digit number)
31523586234912277151…75569548598454575921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.304 × 10⁹⁵(96-digit number)
63047172469824554303…51139097196909151841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.260 × 10⁹⁶(97-digit number)
12609434493964910860…02278194393818303681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.521 × 10⁹⁶(97-digit number)
25218868987929821721…04556388787636607361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.043 × 10⁹⁶(97-digit number)
50437737975859643443…09112777575273214721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.008 × 10⁹⁷(98-digit number)
10087547595171928688…18225555150546429441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.017 × 10⁹⁷(98-digit number)
20175095190343857377…36451110301092858881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.035 × 10⁹⁷(98-digit number)
40350190380687714754…72902220602185717761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
8.070 × 10⁹⁷(98-digit number)
80700380761375429508…45804441204371435521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.614 × 10⁹⁸(99-digit number)
16140076152275085901…91608882408742871041
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:57,607,462 XPM·at block #6,795,424 · updates every 60s
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