Block #502,596

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/20/2014, 1:03:46 PM · Difficulty 10.8071 · 6,302,408 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
a8a7c20e7264c67156cd061a155efb9522c1086fa7dc6bd3be61640fed05db85

Height

#502,596

Difficulty

10.807141

Transactions

8

Size

2.26 KB

Version

2

Bits

0acea0c9

Nonce

24,792

Timestamp

4/20/2014, 1:03:46 PM

Confirmations

6,302,408

Merkle Root

9997a7653f42934d69758003254c91cb4c18cf8681aabb5f677c251dcf245de5
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.

1.119 × 10⁹³(94-digit number)
11191566144892688893…14361590833262488781
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
1.119 × 10⁹³(94-digit number)
11191566144892688893…14361590833262488781
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.238 × 10⁹³(94-digit number)
22383132289785377787…28723181666524977561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.476 × 10⁹³(94-digit number)
44766264579570755574…57446363333049955121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.953 × 10⁹³(94-digit number)
89532529159141511148…14892726666099910241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.790 × 10⁹⁴(95-digit number)
17906505831828302229…29785453332199820481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.581 × 10⁹⁴(95-digit number)
35813011663656604459…59570906664399640961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.162 × 10⁹⁴(95-digit number)
71626023327313208918…19141813328799281921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.432 × 10⁹⁵(96-digit number)
14325204665462641783…38283626657598563841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.865 × 10⁹⁵(96-digit number)
28650409330925283567…76567253315197127681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.730 × 10⁹⁵(96-digit number)
57300818661850567134…53134506630394255361
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:57,684,100 XPM·at block #6,805,003 · updates every 60s
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