Block #282,488

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 11/29/2013, 9:56:49 AM · Difficulty 9.9792 · 6,523,305 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
20e61c3cc10a94efbcb12c4837c440b6a7eef0b4b4727793c857d0fe215faa20

Height

#282,488

Difficulty

9.979219

Transactions

4

Size

1.00 KB

Version

2

Bits

09faae14

Nonce

24,363

Timestamp

11/29/2013, 9:56:49 AM

Confirmations

6,523,305

Merkle Root

e3f42048484b3d4fe9dfff79445fa79d0e6fced39bc2f27f4510df50aa5353dd
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.

9.528 × 10⁹³(94-digit number)
95284027102225437731…72195236931062263179
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
9.528 × 10⁹³(94-digit number)
95284027102225437731…72195236931062263179
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.905 × 10⁹⁴(95-digit number)
19056805420445087546…44390473862124526359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.811 × 10⁹⁴(95-digit number)
38113610840890175092…88780947724249052719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
7.622 × 10⁹⁴(95-digit number)
76227221681780350185…77561895448498105439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.524 × 10⁹⁵(96-digit number)
15245444336356070037…55123790896996210879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.049 × 10⁹⁵(96-digit number)
30490888672712140074…10247581793992421759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.098 × 10⁹⁵(96-digit number)
60981777345424280148…20495163587984843519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.219 × 10⁹⁶(97-digit number)
12196355469084856029…40990327175969687039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.439 × 10⁹⁶(97-digit number)
24392710938169712059…81980654351939374079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.878 × 10⁹⁶(97-digit number)
48785421876339424118…63961308703878748159
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 First 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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,690,427 XPM·at block #6,805,792 · updates every 60s
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