Block #412,059

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 2/20/2014, 7:00:42 AM · Difficulty 10.4145 · 6,384,018 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
f3a3c95f3be38eedb1f522f839835bbd4bf8448057a4ca5339c0987c99f91c32

Height

#412,059

Difficulty

10.414477

Transactions

8

Size

1.71 KB

Version

2

Bits

0a6a1b2a

Nonce

79,836

Timestamp

2/20/2014, 7:00:42 AM

Confirmations

6,384,018

Merkle Root

6f1febb4171b1ba79501ed2ee4e69fe04376b8e3c859d38a50af3aaf1118acc0
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.

4.892 × 10¹⁰¹(102-digit number)
48921809301946976029…21963870245580712961
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
4.892 × 10¹⁰¹(102-digit number)
48921809301946976029…21963870245580712961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.784 × 10¹⁰¹(102-digit number)
97843618603893952058…43927740491161425921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.956 × 10¹⁰²(103-digit number)
19568723720778790411…87855480982322851841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.913 × 10¹⁰²(103-digit number)
39137447441557580823…75710961964645703681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.827 × 10¹⁰²(103-digit number)
78274894883115161646…51421923929291407361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.565 × 10¹⁰³(104-digit number)
15654978976623032329…02843847858582814721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.130 × 10¹⁰³(104-digit number)
31309957953246064658…05687695717165629441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.261 × 10¹⁰³(104-digit number)
62619915906492129317…11375391434331258881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.252 × 10¹⁰⁴(105-digit number)
12523983181298425863…22750782868662517761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.504 × 10¹⁰⁴(105-digit number)
25047966362596851726…45501565737325035521
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:57,612,713 XPM·at block #6,796,076 · updates every 60s
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