Block #3,059,508

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 2/19/2019, 9:19:39 AM · Difficulty 11.0085 · 3,783,473 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
bcdee97bc8db5877854dcb80de6b84592e179269d663357d0f52c24a3ddb7e97

Height

#3,059,508

Difficulty

11.008470

Transactions

5

Size

1.92 KB

Version

2

Bits

0b022b10

Nonce

471,853,246

Timestamp

2/19/2019, 9:19:39 AM

Confirmations

3,783,473

Merkle Root

da772ea77ec61236ea8beaa0faaed581fe09658e1e112312dfd72d880042e5c6
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.

4.749 × 10⁹⁷(98-digit number)
47495116576389825254…25298749312182661121
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
4.749 × 10⁹⁷(98-digit number)
47495116576389825254…25298749312182661121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.499 × 10⁹⁷(98-digit number)
94990233152779650508…50597498624365322241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.899 × 10⁹⁸(99-digit number)
18998046630555930101…01194997248730644481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.799 × 10⁹⁸(99-digit number)
37996093261111860203…02389994497461288961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.599 × 10⁹⁸(99-digit number)
75992186522223720406…04779988994922577921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.519 × 10⁹⁹(100-digit number)
15198437304444744081…09559977989845155841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.039 × 10⁹⁹(100-digit number)
30396874608889488162…19119955979690311681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.079 × 10⁹⁹(100-digit number)
60793749217778976325…38239911959380623361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.215 × 10¹⁰⁰(101-digit number)
12158749843555795265…76479823918761246721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.431 × 10¹⁰⁰(101-digit number)
24317499687111590530…52959647837522493441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
4.863 × 10¹⁰⁰(101-digit number)
48634999374223181060…05919295675044986881
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, …
Circulating Supply:57,988,202 XPM·at block #6,842,980 · updates every 60s
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