Block #3,363,210

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 9/21/2019, 2:57:58 AM · Difficulty 10.9956 · 3,453,088 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
4d3fd1a35a2ce6422827a0d4939c7d4feaa823911783d102d5b8b2c217e3b45f

Height

#3,363,210

Difficulty

10.995591

Transactions

5

Size

1.63 KB

Version

2

Bits

0afedf07

Nonce

25,416,021

Timestamp

9/21/2019, 2:57:58 AM

Confirmations

3,453,088

Merkle Root

f81570750273127ea439caa0c1ce375e75b70951f039323c02126f631f341802
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.

2.292 × 10⁹⁵(96-digit number)
22927866767130682273…76430739715529849921
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
2.292 × 10⁹⁵(96-digit number)
22927866767130682273…76430739715529849921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
4.585 × 10⁹⁵(96-digit number)
45855733534261364546…52861479431059699841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
9.171 × 10⁹⁵(96-digit number)
91711467068522729093…05722958862119399681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.834 × 10⁹⁶(97-digit number)
18342293413704545818…11445917724238799361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.668 × 10⁹⁶(97-digit number)
36684586827409091637…22891835448477598721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
7.336 × 10⁹⁶(97-digit number)
73369173654818183274…45783670896955197441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.467 × 10⁹⁷(98-digit number)
14673834730963636654…91567341793910394881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.934 × 10⁹⁷(98-digit number)
29347669461927273309…83134683587820789761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
5.869 × 10⁹⁷(98-digit number)
58695338923854546619…66269367175641579521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.173 × 10⁹⁸(99-digit number)
11739067784770909323…32538734351283159041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
2.347 × 10⁹⁸(99-digit number)
23478135569541818647…65077468702566318081
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 Second 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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,774,503 XPM·at block #6,816,297 · updates every 60s
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