Block #441,935

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/13/2014, 11:48:21 AM · Difficulty 10.3482 · 6,362,260 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
c268ab2947de325918f634bced9be1731c7830909704c6d9f2b3817dc1d6d9f0

Height

#441,935

Difficulty

10.348235

Transactions

4

Size

1.72 KB

Version

2

Bits

0a5925e6

Nonce

239,283

Timestamp

3/13/2014, 11:48:21 AM

Confirmations

6,362,260

Merkle Root

92fb7a392298623aff487b3d57b0ede8a04f4247e80ac9bb126a0f2bda35f50f
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.

1.082 × 10⁹²(93-digit number)
10828351432284411818…09422893198918169441
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
1.082 × 10⁹²(93-digit number)
10828351432284411818…09422893198918169441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.165 × 10⁹²(93-digit number)
21656702864568823637…18845786397836338881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.331 × 10⁹²(93-digit number)
43313405729137647275…37691572795672677761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.662 × 10⁹²(93-digit number)
86626811458275294551…75383145591345355521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.732 × 10⁹³(94-digit number)
17325362291655058910…50766291182690711041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.465 × 10⁹³(94-digit number)
34650724583310117820…01532582365381422081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
6.930 × 10⁹³(94-digit number)
69301449166620235641…03065164730762844161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.386 × 10⁹⁴(95-digit number)
13860289833324047128…06130329461525688321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.772 × 10⁹⁴(95-digit number)
27720579666648094256…12260658923051376641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.544 × 10⁹⁴(95-digit number)
55441159333296188513…24521317846102753281
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:57,677,614 XPM·at block #6,804,194 · updates every 60s
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