Block #452,376

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/20/2014, 1:09:52 PM · Difficulty 10.3905 · 6,352,424 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
ec853a9c8ba4ab379f79a254b517e4ff39dfd64a481941716ae2a0972575fc6e

Height

#452,376

Difficulty

10.390538

Transactions

6

Size

1.30 KB

Version

2

Bits

0a63fa49

Nonce

67,387

Timestamp

3/20/2014, 1:09:52 PM

Confirmations

6,352,424

Merkle Root

c86c4316c8e9ca229a752867390f2bb2cb8d5b57992da375f19e669abbfc1e4c
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.

1.089 × 10⁹⁵(96-digit number)
10894438580193445176…58990495527608931331
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
1.089 × 10⁹⁵(96-digit number)
10894438580193445176…58990495527608931331
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.178 × 10⁹⁵(96-digit number)
21788877160386890352…17980991055217862661
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.357 × 10⁹⁵(96-digit number)
43577754320773780704…35961982110435725321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.715 × 10⁹⁵(96-digit number)
87155508641547561408…71923964220871450641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.743 × 10⁹⁶(97-digit number)
17431101728309512281…43847928441742901281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.486 × 10⁹⁶(97-digit number)
34862203456619024563…87695856883485802561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
6.972 × 10⁹⁶(97-digit number)
69724406913238049126…75391713766971605121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.394 × 10⁹⁷(98-digit number)
13944881382647609825…50783427533943210241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.788 × 10⁹⁷(98-digit number)
27889762765295219650…01566855067886420481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.577 × 10⁹⁷(98-digit number)
55779525530590439301…03133710135772840961
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:57,682,467 XPM·at block #6,804,799 · updates every 60s
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