Block #333,337

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 12/28/2013, 5:19:36 PM · Difficulty 10.1630 · 6,470,253 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
30ce167f401c37c40d926d75cf72661ec657c284838e23ad78707d7079b3120a

Height

#333,337

Difficulty

10.162976

Transactions

16

Size

4.19 KB

Version

2

Bits

0a29b8c8

Nonce

1,618

Timestamp

12/28/2013, 5:19:36 PM

Confirmations

6,470,253

Merkle Root

b00c903b7280028b2b096ddb0e3666c6a1db16e9d50a3125448aaf576afda10b
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.

4.445 × 10¹⁰²(103-digit number)
44450270222000968217…16048642706072166401
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
4.445 × 10¹⁰²(103-digit number)
44450270222000968217…16048642706072166401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
8.890 × 10¹⁰²(103-digit number)
88900540444001936434…32097285412144332801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.778 × 10¹⁰³(104-digit number)
17780108088800387286…64194570824288665601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.556 × 10¹⁰³(104-digit number)
35560216177600774573…28389141648577331201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.112 × 10¹⁰³(104-digit number)
71120432355201549147…56778283297154662401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.422 × 10¹⁰⁴(105-digit number)
14224086471040309829…13556566594309324801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.844 × 10¹⁰⁴(105-digit number)
28448172942080619658…27113133188618649601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.689 × 10¹⁰⁴(105-digit number)
56896345884161239317…54226266377237299201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.137 × 10¹⁰⁵(106-digit number)
11379269176832247863…08452532754474598401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.275 × 10¹⁰⁵(106-digit number)
22758538353664495727…16905065508949196801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
4.551 × 10¹⁰⁵(106-digit number)
45517076707328991454…33810131017898393601
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,672,757 XPM·at block #6,803,589 · updates every 60s
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