Block #282,763

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 11/29/2013, 12:18:53 PM · Difficulty 9.9798 · 6,519,898 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
93b2d92b714fd4aed7e8551bf156e46ab293efb8367985d3219f9709e7c872d5

Height

#282,763

Difficulty

9.979771

Transactions

7

Size

2.10 KB

Version

2

Bits

09fad24c

Nonce

156,486

Timestamp

11/29/2013, 12:18:53 PM

Confirmations

6,519,898

Merkle Root

9b63a7a133c90e8c8f4c53ba5462482f38cf30bb56e0c2838c834789faa924cb
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.

3.472 × 10⁹⁴(95-digit number)
34728543830925910392…04182455252244889599
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
3.472 × 10⁹⁴(95-digit number)
34728543830925910392…04182455252244889599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
6.945 × 10⁹⁴(95-digit number)
69457087661851820785…08364910504489779199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.389 × 10⁹⁵(96-digit number)
13891417532370364157…16729821008979558399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.778 × 10⁹⁵(96-digit number)
27782835064740728314…33459642017959116799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.556 × 10⁹⁵(96-digit number)
55565670129481456628…66919284035918233599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.111 × 10⁹⁶(97-digit number)
11113134025896291325…33838568071836467199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.222 × 10⁹⁶(97-digit number)
22226268051792582651…67677136143672934399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.445 × 10⁹⁶(97-digit number)
44452536103585165303…35354272287345868799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
8.890 × 10⁹⁶(97-digit number)
88905072207170330606…70708544574691737599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.778 × 10⁹⁷(98-digit number)
17781014441434066121…41417089149383475199
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:57,665,306 XPM·at block #6,802,660 · updates every 60s
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