Block #484,209

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/10/2014, 10:54:27 AM · Difficulty 10.5806 · 6,311,796 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
1f17156688d3bec92e47e883a194b0869f4123e830f9942a10c0be2d0a4dd8f4

Height

#484,209

Difficulty

10.580615

Transactions

15

Size

4.45 KB

Version

2

Bits

0a94a329

Nonce

192,156,722

Timestamp

4/10/2014, 10:54:27 AM

Confirmations

6,311,796

Merkle Root

10614a199abfc4854688febbbe3ce5138f723dc72dd8e4c6e24b1432ba678a2d
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.

1.270 × 10⁹⁸(99-digit number)
12707553502509611460…76361946343441089281
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
1.270 × 10⁹⁸(99-digit number)
12707553502509611460…76361946343441089281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.541 × 10⁹⁸(99-digit number)
25415107005019222920…52723892686882178561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.083 × 10⁹⁸(99-digit number)
50830214010038445841…05447785373764357121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.016 × 10⁹⁹(100-digit number)
10166042802007689168…10895570747528714241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.033 × 10⁹⁹(100-digit number)
20332085604015378336…21791141495057428481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.066 × 10⁹⁹(100-digit number)
40664171208030756673…43582282990114856961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
8.132 × 10⁹⁹(100-digit number)
81328342416061513346…87164565980229713921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.626 × 10¹⁰⁰(101-digit number)
16265668483212302669…74329131960459427841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.253 × 10¹⁰⁰(101-digit number)
32531336966424605338…48658263920918855681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
6.506 × 10¹⁰⁰(101-digit number)
65062673932849210677…97316527841837711361
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:57,612,129 XPM·at block #6,796,004 · updates every 60s
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