Block #314,970

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/16/2013, 6:33:27 AM · Difficulty 10.0820 · 6,484,389 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
80394f5193f6677cc66a63569587232db75f7df52f3cc1cb6e2727d517f7ddea

Height

#314,970

Difficulty

10.081955

Transactions

23

Size

6.50 KB

Version

2

Bits

0a14fb03

Nonce

25,122

Timestamp

12/16/2013, 6:33:27 AM

Confirmations

6,484,389

Merkle Root

5c3a31965c90fbcd4429e71564de807cb65d17b53d3b3865691b9ce95c659d9a
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.

1.882 × 10⁹⁷(98-digit number)
18821253157156553345…93250322792651589121
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
1.882 × 10⁹⁷(98-digit number)
18821253157156553345…93250322792651589121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.764 × 10⁹⁷(98-digit number)
37642506314313106691…86500645585303178241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
7.528 × 10⁹⁷(98-digit number)
75285012628626213382…73001291170606356481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.505 × 10⁹⁸(99-digit number)
15057002525725242676…46002582341212712961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.011 × 10⁹⁸(99-digit number)
30114005051450485353…92005164682425425921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
6.022 × 10⁹⁸(99-digit number)
60228010102900970706…84010329364850851841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.204 × 10⁹⁹(100-digit number)
12045602020580194141…68020658729701703681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.409 × 10⁹⁹(100-digit number)
24091204041160388282…36041317459403407361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.818 × 10⁹⁹(100-digit number)
48182408082320776564…72082634918806814721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
9.636 × 10⁹⁹(100-digit number)
96364816164641553129…44165269837613629441
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:57,638,918 XPM·at block #6,799,358 · updates every 60s
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