Block #352,466

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/10/2014, 8:44:36 AM · Difficulty 10.3086 · 6,462,586 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
8c2f27e54a05241abab2fb7e21f9183e7d5b3dece74a057d171b73d73be1ecdb

Height

#352,466

Difficulty

10.308618

Transactions

1

Size

527 B

Version

2

Bits

0a4f0195

Nonce

535,971

Timestamp

1/10/2014, 8:44:36 AM

Confirmations

6,462,586

Merkle Root

7aa12ab7ccd47f3492c63a2718e8f77f72cd1b20dce3a0eed088894c315fed6a
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.

4.230 × 10⁹³(94-digit number)
42309303802194915867…28323523162524050561
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
4.230 × 10⁹³(94-digit number)
42309303802194915867…28323523162524050561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
8.461 × 10⁹³(94-digit number)
84618607604389831734…56647046325048101121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.692 × 10⁹⁴(95-digit number)
16923721520877966346…13294092650096202241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.384 × 10⁹⁴(95-digit number)
33847443041755932693…26588185300192404481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
6.769 × 10⁹⁴(95-digit number)
67694886083511865387…53176370600384808961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.353 × 10⁹⁵(96-digit number)
13538977216702373077…06352741200769617921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.707 × 10⁹⁵(96-digit number)
27077954433404746155…12705482401539235841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.415 × 10⁹⁵(96-digit number)
54155908866809492310…25410964803078471681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.083 × 10⁹⁶(97-digit number)
10831181773361898462…50821929606156943361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.166 × 10⁹⁶(97-digit number)
21662363546723796924…01643859212313886721
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:57,764,507 XPM·at block #6,815,051 · updates every 60s
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