Block #482,724

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/9/2014, 3:56:30 PM · Difficulty 10.5502 · 6,309,743 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
675cc11ea9690b94c5654ab9027607396417e5a2362c7eb899f27e1656b39b03

Height

#482,724

Difficulty

10.550175

Transactions

2

Size

1.05 KB

Version

2

Bits

0a8cd845

Nonce

2,384,444

Timestamp

4/9/2014, 3:56:30 PM

Confirmations

6,309,743

Merkle Root

a5651d6782f952c503c8ec0192176380d125b50b4b43b26c578afa075d6b9075
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.

3.410 × 10⁹⁹(100-digit number)
34109387718906532194…87441943596125227521
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
3.410 × 10⁹⁹(100-digit number)
34109387718906532194…87441943596125227521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.821 × 10⁹⁹(100-digit number)
68218775437813064388…74883887192250455041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.364 × 10¹⁰⁰(101-digit number)
13643755087562612877…49767774384500910081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.728 × 10¹⁰⁰(101-digit number)
27287510175125225755…99535548769001820161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.457 × 10¹⁰⁰(101-digit number)
54575020350250451510…99071097538003640321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.091 × 10¹⁰¹(102-digit number)
10915004070050090302…98142195076007280641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.183 × 10¹⁰¹(102-digit number)
21830008140100180604…96284390152014561281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.366 × 10¹⁰¹(102-digit number)
43660016280200361208…92568780304029122561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
8.732 × 10¹⁰¹(102-digit number)
87320032560400722417…85137560608058245121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.746 × 10¹⁰²(103-digit number)
17464006512080144483…70275121216116490241
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 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
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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,583,698 XPM·at block #6,792,466 · updates every 60s
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