Block #2,846,590

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 9/19/2018, 5:06:34 PM · Difficulty 11.7298 · 3,998,397 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
8fc4ad1109537697b6a6a98564016ba8d08d1f5edd630694fde85664b4f9d2f6

Height

#2,846,590

Difficulty

11.729779

Transactions

9

Size

2.65 KB

Version

2

Bits

0bbad2cf

Nonce

58,454,188

Timestamp

9/19/2018, 5:06:34 PM

Confirmations

3,998,397

Merkle Root

62ffc985425f0d95c16586f1b3ec33bb5872324c42c2193f4a8c9e9d162b8d5c
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.

1.428 × 10⁹⁷(98-digit number)
14289393991947171199…88573299969380761599
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
1.428 × 10⁹⁷(98-digit number)
14289393991947171199…88573299969380761599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.857 × 10⁹⁷(98-digit number)
28578787983894342399…77146599938761523199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.715 × 10⁹⁷(98-digit number)
57157575967788684798…54293199877523046399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.143 × 10⁹⁸(99-digit number)
11431515193557736959…08586399755046092799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.286 × 10⁹⁸(99-digit number)
22863030387115473919…17172799510092185599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.572 × 10⁹⁸(99-digit number)
45726060774230947838…34345599020184371199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
9.145 × 10⁹⁸(99-digit number)
91452121548461895677…68691198040368742399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.829 × 10⁹⁹(100-digit number)
18290424309692379135…37382396080737484799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.658 × 10⁹⁹(100-digit number)
36580848619384758271…74764792161474969599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
7.316 × 10⁹⁹(100-digit number)
73161697238769516542…49529584322949939199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
1.463 × 10¹⁰⁰(101-digit number)
14632339447753903308…99059168645899878399
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:58,004,315 XPM·at block #6,844,986 · updates every 60s
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