Block #3,668,765

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 5/3/2020, 1:14:35 AM · Difficulty 10.8842 · 3,139,036 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
61ddc5093993414fd6132d21d36e9a527c2182ba21b0fa55fc109a6ae60471a4

Height

#3,668,765

Difficulty

10.884171

Transactions

2

Size

508 B

Version

2

Bits

0ae25903

Nonce

364,980,687

Timestamp

5/3/2020, 1:14:35 AM

Confirmations

3,139,036

Merkle Root

519f52e7937f5f98536c85cdec91bd335eae6921316b154711d2783edafb30ca
Transactions (2)
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.

5.530 × 10⁹⁶(97-digit number)
55300525789357548229…85575590872452162559
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
5.530 × 10⁹⁶(97-digit number)
55300525789357548229…85575590872452162559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.106 × 10⁹⁷(98-digit number)
11060105157871509645…71151181744904325119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.212 × 10⁹⁷(98-digit number)
22120210315743019291…42302363489808650239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.424 × 10⁹⁷(98-digit number)
44240420631486038583…84604726979617300479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
8.848 × 10⁹⁷(98-digit number)
88480841262972077167…69209453959234600959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.769 × 10⁹⁸(99-digit number)
17696168252594415433…38418907918469201919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.539 × 10⁹⁸(99-digit number)
35392336505188830867…76837815836938403839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
7.078 × 10⁹⁸(99-digit number)
70784673010377661734…53675631673876807679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.415 × 10⁹⁹(100-digit number)
14156934602075532346…07351263347753615359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.831 × 10⁹⁹(100-digit number)
28313869204151064693…14702526695507230719
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:57,706,442 XPM·at block #6,807,800 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.

Cookie Preferences

We use cookies to enhance your experience. Some are essential for the site to function, while others help us understand how you use the site.

·Privacy Policy