Block #106,590

2CCLength 9★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 8/9/2013, 2:38:39 AM · Difficulty 9.6100 · 6,687,659 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
1622690b1769844afb0992bad0051c132858b9ced9578991fc629fd4fe24df23

Height

#106,590

Difficulty

9.610012

Transactions

10

Size

2.62 KB

Version

2

Bits

099c29c0

Nonce

1,053

Timestamp

8/9/2013, 2:38:39 AM

Confirmations

6,687,659

Merkle Root

75019d8750ec2763aa5e3cfcb77674b74398fde3ea3e027617cc6467d08997e2
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.

7.414 × 10⁹⁷(98-digit number)
74148076519062759499…78341975220222661361
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
7.414 × 10⁹⁷(98-digit number)
74148076519062759499…78341975220222661361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.482 × 10⁹⁸(99-digit number)
14829615303812551899…56683950440445322721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.965 × 10⁹⁸(99-digit number)
29659230607625103799…13367900880890645441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.931 × 10⁹⁸(99-digit number)
59318461215250207599…26735801761781290881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.186 × 10⁹⁹(100-digit number)
11863692243050041519…53471603523562581761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.372 × 10⁹⁹(100-digit number)
23727384486100083039…06943207047125163521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.745 × 10⁹⁹(100-digit number)
47454768972200166079…13886414094250327041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
9.490 × 10⁹⁹(100-digit number)
94909537944400332158…27772828188500654081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.898 × 10¹⁰⁰(101-digit number)
18981907588880066431…55545656377001308161
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,598,025 XPM·at block #6,794,248 · updates every 60s
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