Block #333,894

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/29/2013, 2:56:16 AM · Difficulty 10.1602 · 6,469,874 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
cc6e673f917a9e0baa065838e4dea75fd95bc8333bc9f50f90206b010b664211

Height

#333,894

Difficulty

10.160159

Transactions

7

Size

2.01 KB

Version

2

Bits

0a29002a

Nonce

247,619

Timestamp

12/29/2013, 2:56:16 AM

Confirmations

6,469,874

Merkle Root

af98cba0a296ad7fe099d971166007f173ec4eea6e218062d8690eb0b9427900
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.

2.399 × 10⁹⁴(95-digit number)
23999349863669853659…92378692401991070721
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
2.399 × 10⁹⁴(95-digit number)
23999349863669853659…92378692401991070721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
4.799 × 10⁹⁴(95-digit number)
47998699727339707319…84757384803982141441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
9.599 × 10⁹⁴(95-digit number)
95997399454679414639…69514769607964282881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.919 × 10⁹⁵(96-digit number)
19199479890935882927…39029539215928565761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.839 × 10⁹⁵(96-digit number)
38398959781871765855…78059078431857131521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
7.679 × 10⁹⁵(96-digit number)
76797919563743531711…56118156863714263041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.535 × 10⁹⁶(97-digit number)
15359583912748706342…12236313727428526081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.071 × 10⁹⁶(97-digit number)
30719167825497412684…24472627454857052161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.143 × 10⁹⁶(97-digit number)
61438335650994825369…48945254909714104321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.228 × 10⁹⁷(98-digit number)
12287667130198965073…97890509819428208641
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:57,674,182 XPM·at block #6,803,767 · updates every 60s
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