Block #383,676

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/31/2014, 1:55:59 PM · Difficulty 10.4031 · 6,414,706 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
b5ba776dd867df38c891961db9e7aa2b3e9f3089cb4c128ba18070ca415cbe47

Height

#383,676

Difficulty

10.403110

Transactions

3

Size

986 B

Version

2

Bits

0a673231

Nonce

117,264

Timestamp

1/31/2014, 1:55:59 PM

Confirmations

6,414,706

Merkle Root

5f6b1819238df2941e57321536a90d1af6fa38b3d14460b5bf1ba2918d45abc6
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.

6.634 × 10¹⁰⁰(101-digit number)
66344146706595915075…06436930788939499519
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
6.634 × 10¹⁰⁰(101-digit number)
66344146706595915075…06436930788939499519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.326 × 10¹⁰¹(102-digit number)
13268829341319183015…12873861577878999039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.653 × 10¹⁰¹(102-digit number)
26537658682638366030…25747723155757998079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.307 × 10¹⁰¹(102-digit number)
53075317365276732060…51495446311515996159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.061 × 10¹⁰²(103-digit number)
10615063473055346412…02990892623031992319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.123 × 10¹⁰²(103-digit number)
21230126946110692824…05981785246063984639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.246 × 10¹⁰²(103-digit number)
42460253892221385648…11963570492127969279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.492 × 10¹⁰²(103-digit number)
84920507784442771296…23927140984255938559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.698 × 10¹⁰³(104-digit number)
16984101556888554259…47854281968511877119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.396 × 10¹⁰³(104-digit number)
33968203113777108518…95708563937023754239
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:57,631,062 XPM·at block #6,798,381 · updates every 60s
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