Block #282,897

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 11/29/2013, 1:23:14 PM · Difficulty 9.9801 · 6,544,214 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
cc096bf8588b9bad59e788570251b5f92400b9dbfc5663fe714a5ef14fee4d2d

Height

#282,897

Difficulty

9.980057

Transactions

1

Size

1.11 KB

Version

2

Bits

09fae50c

Nonce

570,244

Timestamp

11/29/2013, 1:23:14 PM

Confirmations

6,544,214

Merkle Root

7af1ba6c016b3a52f94579bbc0db0c7832d085b703d5a5c3203aedeee9cd1d92
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.

1.209 × 10⁹²(93-digit number)
12091994180782104201…86229457316789599999
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
1.209 × 10⁹²(93-digit number)
12091994180782104201…86229457316789599999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.418 × 10⁹²(93-digit number)
24183988361564208403…72458914633579199999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.836 × 10⁹²(93-digit number)
48367976723128416806…44917829267158399999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
9.673 × 10⁹²(93-digit number)
96735953446256833612…89835658534316799999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.934 × 10⁹³(94-digit number)
19347190689251366722…79671317068633599999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.869 × 10⁹³(94-digit number)
38694381378502733445…59342634137267199999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
7.738 × 10⁹³(94-digit number)
77388762757005466890…18685268274534399999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.547 × 10⁹⁴(95-digit number)
15477752551401093378…37370536549068799999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.095 × 10⁹⁴(95-digit number)
30955505102802186756…74741073098137599999
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,861,067 XPM·at block #6,827,110 · updates every 60s
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