Block #492,582

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/15/2014, 5:50:16 AM · Difficulty 10.6881 · 6,313,047 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
8bbabcda7d7be663065cf2f91448aa5609887639b56370a3e29e10f7f79fc3e9

Height

#492,582

Difficulty

10.688150

Transactions

4

Size

1.16 KB

Version

2

Bits

0ab02a95

Nonce

8,322,208

Timestamp

4/15/2014, 5:50:16 AM

Confirmations

6,313,047

Merkle Root

25c5765f74d3e1b8a58281f747d243e1740bef3818964998c957a4f1e76a001d
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.

4.849 × 10⁹⁸(99-digit number)
48496672421391006861…72808929284217650561
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
4.849 × 10⁹⁸(99-digit number)
48496672421391006861…72808929284217650561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.699 × 10⁹⁸(99-digit number)
96993344842782013722…45617858568435301121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.939 × 10⁹⁹(100-digit number)
19398668968556402744…91235717136870602241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.879 × 10⁹⁹(100-digit number)
38797337937112805488…82471434273741204481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.759 × 10⁹⁹(100-digit number)
77594675874225610977…64942868547482408961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.551 × 10¹⁰⁰(101-digit number)
15518935174845122195…29885737094964817921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.103 × 10¹⁰⁰(101-digit number)
31037870349690244391…59771474189929635841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.207 × 10¹⁰⁰(101-digit number)
62075740699380488782…19542948379859271681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.241 × 10¹⁰¹(102-digit number)
12415148139876097756…39085896759718543361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.483 × 10¹⁰¹(102-digit number)
24830296279752195512…78171793519437086721
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:57,689,107 XPM·at block #6,805,628 · updates every 60s
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