Block #462,145

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/27/2014, 6:28:43 AM · Difficulty 10.4086 · 6,340,522 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
83728d7728996d02879ac05bd34395bd5bb210d1f01541c417fdf56ef05b78a1

Height

#462,145

Difficulty

10.408587

Transactions

18

Size

146.29 KB

Version

2

Bits

0a68992f

Nonce

91,259,043

Timestamp

3/27/2014, 6:28:43 AM

Confirmations

6,340,522

Merkle Root

fc0304716433edcc9563527a71ce9143e3f4fff8a4e2d0269597fc36de49c364
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.

2.650 × 10⁹⁶(97-digit number)
26504805931389317029…21278504115843384321
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
2.650 × 10⁹⁶(97-digit number)
26504805931389317029…21278504115843384321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.300 × 10⁹⁶(97-digit number)
53009611862778634058…42557008231686768641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.060 × 10⁹⁷(98-digit number)
10601922372555726811…85114016463373537281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.120 × 10⁹⁷(98-digit number)
21203844745111453623…70228032926747074561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.240 × 10⁹⁷(98-digit number)
42407689490222907246…40456065853494149121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
8.481 × 10⁹⁷(98-digit number)
84815378980445814492…80912131706988298241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.696 × 10⁹⁸(99-digit number)
16963075796089162898…61824263413976596481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.392 × 10⁹⁸(99-digit number)
33926151592178325797…23648526827953192961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.785 × 10⁹⁸(99-digit number)
67852303184356651594…47297053655906385921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.357 × 10⁹⁹(100-digit number)
13570460636871330318…94594107311812771841
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:57,665,355 XPM·at block #6,802,666 · updates every 60s
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