Block #507,224

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/23/2014, 2:25:57 PM · Difficulty 10.8160 · 6,296,232 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
ba535fc54ed821f2fc2f9106066aebbff8e94fbc52fdfb7d9046c3af1043b8c0

Height

#507,224

Difficulty

10.816001

Transactions

5

Size

2.37 KB

Version

2

Bits

0ad0e56f

Nonce

29,490,981

Timestamp

4/23/2014, 2:25:57 PM

Confirmations

6,296,232

Merkle Root

5520fbda93392952397f206d8d7ed03d54c5e780128593babdc4976ed5f7b398
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.

3.156 × 10⁹⁹(100-digit number)
31560873774873491106…39717478833451058241
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
3.156 × 10⁹⁹(100-digit number)
31560873774873491106…39717478833451058241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.312 × 10⁹⁹(100-digit number)
63121747549746982212…79434957666902116481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.262 × 10¹⁰⁰(101-digit number)
12624349509949396442…58869915333804232961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.524 × 10¹⁰⁰(101-digit number)
25248699019898792884…17739830667608465921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.049 × 10¹⁰⁰(101-digit number)
50497398039797585769…35479661335216931841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.009 × 10¹⁰¹(102-digit number)
10099479607959517153…70959322670433863681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.019 × 10¹⁰¹(102-digit number)
20198959215919034307…41918645340867727361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.039 × 10¹⁰¹(102-digit number)
40397918431838068615…83837290681735454721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
8.079 × 10¹⁰¹(102-digit number)
80795836863676137231…67674581363470909441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.615 × 10¹⁰²(103-digit number)
16159167372735227446…35349162726941818881
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:57,671,675 XPM·at block #6,803,455 · updates every 60s
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