Block #323,235

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/21/2013, 12:33:58 PM · Difficulty 10.2033 · 6,482,822 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
d7ac48b06095b3149e6202d79a0345e0b77a716eff8073b11c9a9bd07774815f

Height

#323,235

Difficulty

10.203305

Transactions

13

Size

2.85 KB

Version

2

Bits

0a340bc4

Nonce

11,057

Timestamp

12/21/2013, 12:33:58 PM

Confirmations

6,482,822

Merkle Root

382f206a8e2f6a67f04af674a915e450cfd2dcbc841e47a4227651eabacb3184
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.

4.065 × 10⁹⁸(99-digit number)
40659082736675546697…09207968995750624001
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
4.065 × 10⁹⁸(99-digit number)
40659082736675546697…09207968995750624001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
8.131 × 10⁹⁸(99-digit number)
81318165473351093395…18415937991501248001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.626 × 10⁹⁹(100-digit number)
16263633094670218679…36831875983002496001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.252 × 10⁹⁹(100-digit number)
32527266189340437358…73663751966004992001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
6.505 × 10⁹⁹(100-digit number)
65054532378680874716…47327503932009984001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.301 × 10¹⁰⁰(101-digit number)
13010906475736174943…94655007864019968001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.602 × 10¹⁰⁰(101-digit number)
26021812951472349886…89310015728039936001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.204 × 10¹⁰⁰(101-digit number)
52043625902944699772…78620031456079872001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.040 × 10¹⁰¹(102-digit number)
10408725180588939954…57240062912159744001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.081 × 10¹⁰¹(102-digit number)
20817450361177879909…14480125824319488001
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:57,692,539 XPM·at block #6,806,056 · updates every 60s
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