Block #3,012,092

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 1/16/2019, 2:15:37 PM · Difficulty 11.1755 · 3,827,988 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
fb22b0a61681db48bee239b9e2146eb936bc0032244ee90a6b2bee9fb3700472

Height

#3,012,092

Difficulty

11.175525

Transactions

65

Size

14.43 KB

Version

2

Bits

0b2cef3b

Nonce

6,296,288

Timestamp

1/16/2019, 2:15:37 PM

Confirmations

3,827,988

Merkle Root

44d1775a07eb815896a3ef167ca92b78942e7a05af6c15861860850813b810cd
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.

1.967 × 10⁹⁶(97-digit number)
19678470814672258292…47776377936393728001
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
1.967 × 10⁹⁶(97-digit number)
19678470814672258292…47776377936393728001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.935 × 10⁹⁶(97-digit number)
39356941629344516584…95552755872787456001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
7.871 × 10⁹⁶(97-digit number)
78713883258689033169…91105511745574912001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.574 × 10⁹⁷(98-digit number)
15742776651737806633…82211023491149824001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.148 × 10⁹⁷(98-digit number)
31485553303475613267…64422046982299648001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
6.297 × 10⁹⁷(98-digit number)
62971106606951226535…28844093964599296001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.259 × 10⁹⁸(99-digit number)
12594221321390245307…57688187929198592001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.518 × 10⁹⁸(99-digit number)
25188442642780490614…15376375858397184001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
5.037 × 10⁹⁸(99-digit number)
50376885285560981228…30752751716794368001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.007 × 10⁹⁹(100-digit number)
10075377057112196245…61505503433588736001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
2.015 × 10⁹⁹(100-digit number)
20150754114224392491…23011006867177472001
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, …
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