Block #508,028

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/24/2014, 3:21:11 AM · Difficulty 10.8175 · 6,288,258 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
a86d485bd783c35209a4c4449ec45d615a56c01c1131f317e58f147cdffb5e4b

Height

#508,028

Difficulty

10.817521

Transactions

8

Size

2.83 KB

Version

2

Bits

0ad14908

Nonce

473,769

Timestamp

4/24/2014, 3:21:11 AM

Confirmations

6,288,258

Merkle Root

d55ddba60ff23bd9d0fc36502798c8e8d3e8cab0cb74e609ed0be637e0e11415
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.

6.304 × 10⁹³(94-digit number)
63044148391053461949…64537665666197145351
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
6.304 × 10⁹³(94-digit number)
63044148391053461949…64537665666197145351
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.260 × 10⁹⁴(95-digit number)
12608829678210692389…29075331332394290701
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.521 × 10⁹⁴(95-digit number)
25217659356421384779…58150662664788581401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.043 × 10⁹⁴(95-digit number)
50435318712842769559…16301325329577162801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.008 × 10⁹⁵(96-digit number)
10087063742568553911…32602650659154325601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.017 × 10⁹⁵(96-digit number)
20174127485137107823…65205301318308651201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.034 × 10⁹⁵(96-digit number)
40348254970274215647…30410602636617302401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
8.069 × 10⁹⁵(96-digit number)
80696509940548431295…60821205273234604801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.613 × 10⁹⁶(97-digit number)
16139301988109686259…21642410546469209601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.227 × 10⁹⁶(97-digit number)
32278603976219372518…43284821092938419201
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:57,614,291 XPM·at block #6,796,285 · updates every 60s
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