Block #379,275

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/28/2014, 10:36:53 AM · Difficulty 10.4157 · 6,416,591 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
468b407a23598aa2326ed8030149b02cdb62c300ab76f61a03b06a281c687a2b

Height

#379,275

Difficulty

10.415729

Transactions

11

Size

2.55 KB

Version

2

Bits

0a6a6d34

Nonce

142,951

Timestamp

1/28/2014, 10:36:53 AM

Confirmations

6,416,591

Merkle Root

419322354677cad8a94b0e205c3bd2a90d8ac4a0a1cf2e48374ef287fe38a8e4
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.

2.444 × 10⁹⁷(98-digit number)
24441348761802646940…69936947573284739201
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
2.444 × 10⁹⁷(98-digit number)
24441348761802646940…69936947573284739201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
4.888 × 10⁹⁷(98-digit number)
48882697523605293881…39873895146569478401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
9.776 × 10⁹⁷(98-digit number)
97765395047210587762…79747790293138956801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.955 × 10⁹⁸(99-digit number)
19553079009442117552…59495580586277913601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.910 × 10⁹⁸(99-digit number)
39106158018884235105…18991161172555827201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
7.821 × 10⁹⁸(99-digit number)
78212316037768470210…37982322345111654401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.564 × 10⁹⁹(100-digit number)
15642463207553694042…75964644690223308801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.128 × 10⁹⁹(100-digit number)
31284926415107388084…51929289380446617601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.256 × 10⁹⁹(100-digit number)
62569852830214776168…03858578760893235201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.251 × 10¹⁰⁰(101-digit number)
12513970566042955233…07717157521786470401
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:57,611,015 XPM·at block #6,795,865 · updates every 60s
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