Block #326,764

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/24/2013, 1:09:55 AM · Difficulty 10.1867 · 6,478,124 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
daac7974eeafc78e00f81a4a5f0c6e2e727a917a6a69b4ae623a0a3fc5c24882

Height

#326,764

Difficulty

10.186708

Transactions

25

Size

7.82 KB

Version

2

Bits

0a2fcc1d

Nonce

67,068

Timestamp

12/24/2013, 1:09:55 AM

Confirmations

6,478,124

Merkle Root

a36a98faa8476c0b16be0d85f93b5d59a707db819020464fab2f716c2a5c7ae6
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.

1.424 × 10¹⁰¹(102-digit number)
14241832895629813617…16800991376154869759
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
1.424 × 10¹⁰¹(102-digit number)
14241832895629813617…16800991376154869759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.848 × 10¹⁰¹(102-digit number)
28483665791259627234…33601982752309739519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.696 × 10¹⁰¹(102-digit number)
56967331582519254469…67203965504619479039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.139 × 10¹⁰²(103-digit number)
11393466316503850893…34407931009238958079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.278 × 10¹⁰²(103-digit number)
22786932633007701787…68815862018477916159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.557 × 10¹⁰²(103-digit number)
45573865266015403575…37631724036955832319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
9.114 × 10¹⁰²(103-digit number)
91147730532030807150…75263448073911664639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.822 × 10¹⁰³(104-digit number)
18229546106406161430…50526896147823329279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.645 × 10¹⁰³(104-digit number)
36459092212812322860…01053792295646658559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
7.291 × 10¹⁰³(104-digit number)
72918184425624645720…02107584591293317119
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:57,683,181 XPM·at block #6,804,887 · updates every 60s
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