Block #3,058,879

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 2/18/2019, 10:41:29 PM · Difficulty 11.0102 · 3,782,449 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
f65180677c9ce2a6bea623f8e65af57f58f618136dbca2419de9baa2c9160833

Height

#3,058,879

Difficulty

11.010216

Transactions

4

Size

1.19 KB

Version

2

Bits

0b029d88

Nonce

1,676,226,231

Timestamp

2/18/2019, 10:41:29 PM

Confirmations

3,782,449

Merkle Root

b16462a6217a4757616dd989bb668d3791f0b3728a72ff596cb0c3328c249296
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.

6.717 × 10⁹⁴(95-digit number)
67170604387333633056…27039150881464736801
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
6.717 × 10⁹⁴(95-digit number)
67170604387333633056…27039150881464736801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.343 × 10⁹⁵(96-digit number)
13434120877466726611…54078301762929473601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.686 × 10⁹⁵(96-digit number)
26868241754933453222…08156603525858947201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.373 × 10⁹⁵(96-digit number)
53736483509866906445…16313207051717894401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.074 × 10⁹⁶(97-digit number)
10747296701973381289…32626414103435788801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.149 × 10⁹⁶(97-digit number)
21494593403946762578…65252828206871577601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.298 × 10⁹⁶(97-digit number)
42989186807893525156…30505656413743155201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
8.597 × 10⁹⁶(97-digit number)
85978373615787050312…61011312827486310401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.719 × 10⁹⁷(98-digit number)
17195674723157410062…22022625654972620801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.439 × 10⁹⁷(98-digit number)
34391349446314820125…44045251309945241601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
6.878 × 10⁹⁷(98-digit number)
68782698892629640250…88090502619890483201
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:57,974,987 XPM·at block #6,841,327 · updates every 60s
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