Block #457,985

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/24/2014, 7:02:44 AM · Difficulty 10.4196 · 6,351,136 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
b753b6f5a6e9042739f916c3c2071a1dd18452940c90c52c45aa4305d5b11c91

Height

#457,985

Difficulty

10.419597

Transactions

2

Size

4.18 KB

Version

2

Bits

0a6b6aaf

Nonce

54,110

Timestamp

3/24/2014, 7:02:44 AM

Confirmations

6,351,136

Merkle Root

e46eb54685d71ec2761e0c6a7cae6aeb364457d6a7947dbb593d5d9e69111880
Transactions (2)
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.

2.194 × 10⁹⁷(98-digit number)
21948199677353701789…83796202135483906641
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
2.194 × 10⁹⁷(98-digit number)
21948199677353701789…83796202135483906641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
4.389 × 10⁹⁷(98-digit number)
43896399354707403579…67592404270967813281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
8.779 × 10⁹⁷(98-digit number)
87792798709414807158…35184808541935626561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.755 × 10⁹⁸(99-digit number)
17558559741882961431…70369617083871253121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.511 × 10⁹⁸(99-digit number)
35117119483765922863…40739234167742506241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
7.023 × 10⁹⁸(99-digit number)
70234238967531845726…81478468335485012481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.404 × 10⁹⁹(100-digit number)
14046847793506369145…62956936670970024961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.809 × 10⁹⁹(100-digit number)
28093695587012738290…25913873341940049921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
5.618 × 10⁹⁹(100-digit number)
56187391174025476581…51827746683880099841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.123 × 10¹⁰⁰(101-digit number)
11237478234805095316…03655493367760199681
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:57,717,026 XPM·at block #6,809,120 · updates every 60s
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