Block #2,762,022

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 7/23/2018, 7:33:40 PM · Difficulty 11.6543 · 4,048,893 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
85bc283e96d7d62e531710988f5efc1ceb77a51f10b2b6d38e98699eb7bbd08a

Height

#2,762,022

Difficulty

11.654318

Transactions

6

Size

3.73 KB

Version

2

Bits

0ba7815c

Nonce

55,053,557

Timestamp

7/23/2018, 7:33:40 PM

Confirmations

4,048,893

Merkle Root

719d504c2f609a7f96d23fd8d04fa840b8c6406f046b78d5be0b64359b001523
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.

8.666 × 10⁹⁴(95-digit number)
86660578060316797024…67755138463386523519
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
8.666 × 10⁹⁴(95-digit number)
86660578060316797024…67755138463386523519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.733 × 10⁹⁵(96-digit number)
17332115612063359404…35510276926773047039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.466 × 10⁹⁵(96-digit number)
34664231224126718809…71020553853546094079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
6.932 × 10⁹⁵(96-digit number)
69328462448253437619…42041107707092188159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.386 × 10⁹⁶(97-digit number)
13865692489650687523…84082215414184376319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.773 × 10⁹⁶(97-digit number)
27731384979301375047…68164430828368752639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.546 × 10⁹⁶(97-digit number)
55462769958602750095…36328861656737505279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.109 × 10⁹⁷(98-digit number)
11092553991720550019…72657723313475010559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.218 × 10⁹⁷(98-digit number)
22185107983441100038…45315446626950021119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.437 × 10⁹⁷(98-digit number)
44370215966882200076…90630893253900042239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
8.874 × 10⁹⁷(98-digit number)
88740431933764400152…81261786507800084479
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:57,731,421 XPM·at block #6,810,914 · updates every 60s
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