Block #330,447

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/26/2013, 4:19:13 PM · Difficulty 10.1703 · 6,462,204 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
ce83b7be411fc3ae90d503f342b681900b6d97ac48d124123637ac78555c3bde

Height

#330,447

Difficulty

10.170278

Transactions

15

Size

8.34 KB

Version

2

Bits

0a2b974f

Nonce

13,802

Timestamp

12/26/2013, 4:19:13 PM

Confirmations

6,462,204

Merkle Root

582afbb230e3a9ecdf7b4692a6c9816ec17074939fc0611a570e6d2fa0155d27
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.

1.104 × 10⁹⁸(99-digit number)
11048028548649895368…83051247155631317761
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
1.104 × 10⁹⁸(99-digit number)
11048028548649895368…83051247155631317761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.209 × 10⁹⁸(99-digit number)
22096057097299790736…66102494311262635521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.419 × 10⁹⁸(99-digit number)
44192114194599581472…32204988622525271041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.838 × 10⁹⁸(99-digit number)
88384228389199162944…64409977245050542081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.767 × 10⁹⁹(100-digit number)
17676845677839832588…28819954490101084161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.535 × 10⁹⁹(100-digit number)
35353691355679665177…57639908980202168321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.070 × 10⁹⁹(100-digit number)
70707382711359330355…15279817960404336641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.414 × 10¹⁰⁰(101-digit number)
14141476542271866071…30559635920808673281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.828 × 10¹⁰⁰(101-digit number)
28282953084543732142…61119271841617346561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.656 × 10¹⁰⁰(101-digit number)
56565906169087464284…22238543683234693121
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:57,585,176 XPM·at block #6,792,650 · updates every 60s
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