Block #470,419

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/1/2014, 9:27:25 PM · Difficulty 10.4330 · 6,324,175 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
54dd9d2fd8a03c82c6ca94daae041c8606596fcaec51cf8de7f53d9c9ca3fef5

Height

#470,419

Difficulty

10.433010

Transactions

6

Size

2.75 KB

Version

2

Bits

0a6ed9c2

Nonce

59,925,971

Timestamp

4/1/2014, 9:27:25 PM

Confirmations

6,324,175

Merkle Root

212930b4982444327116ee626ec5bf04e6ee4292cb7e9672baaca1eee127aae6
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.

5.967 × 10⁹⁵(96-digit number)
59672768302575559028…93514681082430760001
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
5.967 × 10⁹⁵(96-digit number)
59672768302575559028…93514681082430760001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.193 × 10⁹⁶(97-digit number)
11934553660515111805…87029362164861520001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.386 × 10⁹⁶(97-digit number)
23869107321030223611…74058724329723040001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.773 × 10⁹⁶(97-digit number)
47738214642060447222…48117448659446080001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
9.547 × 10⁹⁶(97-digit number)
95476429284120894445…96234897318892160001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.909 × 10⁹⁷(98-digit number)
19095285856824178889…92469794637784320001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.819 × 10⁹⁷(98-digit number)
38190571713648357778…84939589275568640001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
7.638 × 10⁹⁷(98-digit number)
76381143427296715556…69879178551137280001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.527 × 10⁹⁸(99-digit number)
15276228685459343111…39758357102274560001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.055 × 10⁹⁸(99-digit number)
30552457370918686222…79516714204549120001
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:57,600,793 XPM·at block #6,794,593 · updates every 60s
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