Block #338,894

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/1/2014, 5:53:42 PM · Difficulty 10.1250 · 6,460,638 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
febd4917fc0b68813b08fb52c991fafefc4db5392bd04087f38a0aa2628fbb27

Height

#338,894

Difficulty

10.125029

Transactions

5

Size

1.34 KB

Version

2

Bits

0a2001e4

Nonce

25,190

Timestamp

1/1/2014, 5:53:42 PM

Confirmations

6,460,638

Merkle Root

ff439d4bf183ebab5e1b151255251c8be357816dad17192ba52a4fbf5694392f
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.

1.317 × 10¹⁰³(104-digit number)
13179890225170241545…58039575063750121599
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
1.317 × 10¹⁰³(104-digit number)
13179890225170241545…58039575063750121599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.635 × 10¹⁰³(104-digit number)
26359780450340483091…16079150127500243199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.271 × 10¹⁰³(104-digit number)
52719560900680966183…32158300255000486399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.054 × 10¹⁰⁴(105-digit number)
10543912180136193236…64316600510000972799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.108 × 10¹⁰⁴(105-digit number)
21087824360272386473…28633201020001945599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.217 × 10¹⁰⁴(105-digit number)
42175648720544772947…57266402040003891199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
8.435 × 10¹⁰⁴(105-digit number)
84351297441089545894…14532804080007782399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.687 × 10¹⁰⁵(106-digit number)
16870259488217909178…29065608160015564799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.374 × 10¹⁰⁵(106-digit number)
33740518976435818357…58131216320031129599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
6.748 × 10¹⁰⁵(106-digit number)
67481037952871636715…16262432640062259199
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:57,640,306 XPM·at block #6,799,531 · updates every 60s
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