Block #3,292,459

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 8/2/2019, 3:16:00 PM · Difficulty 10.9949 · 3,513,394 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
6d2c7e08e02e3c1c76ed3415d9f37b1b0a8fedee887ab2bd8ee37f9288893339

Height

#3,292,459

Difficulty

10.994914

Transactions

5

Size

2.52 KB

Version

2

Bits

0afeb2ae

Nonce

8,893,531

Timestamp

8/2/2019, 3:16:00 PM

Confirmations

3,513,394

Merkle Root

4978db15f2661f5802187b1d3b9500a5b378cb3082c67d69ac0c6c7b1e0a721b
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.

4.070 × 10⁹⁶(97-digit number)
40701377325796040280…36909253375670732801
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
4.070 × 10⁹⁶(97-digit number)
40701377325796040280…36909253375670732801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
8.140 × 10⁹⁶(97-digit number)
81402754651592080561…73818506751341465601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.628 × 10⁹⁷(98-digit number)
16280550930318416112…47637013502682931201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.256 × 10⁹⁷(98-digit number)
32561101860636832224…95274027005365862401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
6.512 × 10⁹⁷(98-digit number)
65122203721273664448…90548054010731724801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.302 × 10⁹⁸(99-digit number)
13024440744254732889…81096108021463449601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.604 × 10⁹⁸(99-digit number)
26048881488509465779…62192216042926899201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.209 × 10⁹⁸(99-digit number)
52097762977018931559…24384432085853798401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.041 × 10⁹⁹(100-digit number)
10419552595403786311…48768864171707596801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.083 × 10⁹⁹(100-digit number)
20839105190807572623…97537728343415193601
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:57,690,905 XPM·at block #6,805,852 · updates every 60s
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