Block #330,835

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/26/2013, 11:03:50 PM · Difficulty 10.1678 · 6,475,423 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
0a1dcb91e499f728be004a587926e21df1347d793b135e31c48bbc3951f39b2b

Height

#330,835

Difficulty

10.167771

Transactions

17

Size

10.71 KB

Version

2

Bits

0a2af307

Nonce

13,601

Timestamp

12/26/2013, 11:03:50 PM

Confirmations

6,475,423

Merkle Root

2fe76087c2f4f84962dbe3afbf192b760ac631c54e80445e70dc15d5c2a35994
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.

3.711 × 10⁹⁵(96-digit number)
37111884120598234102…42604126299221892081
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
3.711 × 10⁹⁵(96-digit number)
37111884120598234102…42604126299221892081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
7.422 × 10⁹⁵(96-digit number)
74223768241196468205…85208252598443784161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.484 × 10⁹⁶(97-digit number)
14844753648239293641…70416505196887568321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.968 × 10⁹⁶(97-digit number)
29689507296478587282…40833010393775136641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.937 × 10⁹⁶(97-digit number)
59379014592957174564…81666020787550273281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.187 × 10⁹⁷(98-digit number)
11875802918591434912…63332041575100546561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.375 × 10⁹⁷(98-digit number)
23751605837182869825…26664083150201093121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.750 × 10⁹⁷(98-digit number)
47503211674365739651…53328166300402186241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
9.500 × 10⁹⁷(98-digit number)
95006423348731479303…06656332600804372481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.900 × 10⁹⁸(99-digit number)
19001284669746295860…13312665201608744961
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:57,694,148 XPM·at block #6,806,257 · updates every 60s
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