Block #2,114,373

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/13/2017, 2:42:32 PM · Difficulty 10.9001 · 4,728,184 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
35657c6d81c5c9fde9c0a9f3a1b661ab1ae98d1b9a4e90246d90aed4f7f6a44d

Height

#2,114,373

Difficulty

10.900084

Transactions

29

Size

9.77 KB

Version

2

Bits

0ae66bea

Nonce

1,162,854,173

Timestamp

5/13/2017, 2:42:32 PM

Confirmations

4,728,184

Merkle Root

44e8eae0ee3074f9fad1e2761dcb4bc84c9742122596bbbce058443f2a0b468a
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.

1.042 × 10⁹²(93-digit number)
10429012844012126601…27530709522011857841
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
1.042 × 10⁹²(93-digit number)
10429012844012126601…27530709522011857841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.085 × 10⁹²(93-digit number)
20858025688024253202…55061419044023715681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.171 × 10⁹²(93-digit number)
41716051376048506404…10122838088047431361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.343 × 10⁹²(93-digit number)
83432102752097012808…20245676176094862721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.668 × 10⁹³(94-digit number)
16686420550419402561…40491352352189725441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.337 × 10⁹³(94-digit number)
33372841100838805123…80982704704379450881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
6.674 × 10⁹³(94-digit number)
66745682201677610246…61965409408758901761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.334 × 10⁹⁴(95-digit number)
13349136440335522049…23930818817517803521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.669 × 10⁹⁴(95-digit number)
26698272880671044098…47861637635035607041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.339 × 10⁹⁴(95-digit number)
53396545761342088197…95723275270071214081
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:57,984,882 XPM·at block #6,842,556 · updates every 60s
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