Block #448,617

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 3/18/2014, 1:38:08 AM · Difficulty 10.3657 · 6,357,218 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
42f7b98dd402f07c2a06bb384acc4764b353fe17107153a0f97378761f2aedf0

Height

#448,617

Difficulty

10.365689

Transactions

2

Size

1.14 KB

Version

2

Bits

0a5d9dcb

Nonce

137,256

Timestamp

3/18/2014, 1:38:08 AM

Confirmations

6,357,218

Merkle Root

770b8788ff673e7b32aadfba8b841bb5257bab260aef1aead2fdc0bd23c3cdb3
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.

5.210 × 10⁹⁸(99-digit number)
52102827730374487909…44636960811308378879
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
5.210 × 10⁹⁸(99-digit number)
52102827730374487909…44636960811308378879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.042 × 10⁹⁹(100-digit number)
10420565546074897581…89273921622616757759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.084 × 10⁹⁹(100-digit number)
20841131092149795163…78547843245233515519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.168 × 10⁹⁹(100-digit number)
41682262184299590327…57095686490467031039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
8.336 × 10⁹⁹(100-digit number)
83364524368599180654…14191372980934062079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.667 × 10¹⁰⁰(101-digit number)
16672904873719836130…28382745961868124159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.334 × 10¹⁰⁰(101-digit number)
33345809747439672261…56765491923736248319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.669 × 10¹⁰⁰(101-digit number)
66691619494879344523…13530983847472496639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.333 × 10¹⁰¹(102-digit number)
13338323898975868904…27061967694944993279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.667 × 10¹⁰¹(102-digit number)
26676647797951737809…54123935389889986559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
5.335 × 10¹⁰¹(102-digit number)
53353295595903475619…08247870779779973119
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,690,765 XPM·at block #6,805,834 · updates every 60s
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