Block #335,342

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/30/2013, 3:56:30 AM · Difficulty 10.1522 · 6,474,925 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
41a67f98cee82351e38e467b17ab39445f4ec1106111d5d6361a12206d7a50d2

Height

#335,342

Difficulty

10.152207

Transactions

5

Size

1.47 KB

Version

2

Bits

0a26f707

Nonce

97,628

Timestamp

12/30/2013, 3:56:30 AM

Confirmations

6,474,925

Merkle Root

ffec8b22f45722e0de58fdb586fa17c1e7ea698bafbaf3ef33fb2317c93039fd
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.

4.358 × 10⁹⁵(96-digit number)
43589524487117959057…95163773958039570241
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
4.358 × 10⁹⁵(96-digit number)
43589524487117959057…95163773958039570241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
8.717 × 10⁹⁵(96-digit number)
87179048974235918115…90327547916079140481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.743 × 10⁹⁶(97-digit number)
17435809794847183623…80655095832158280961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.487 × 10⁹⁶(97-digit number)
34871619589694367246…61310191664316561921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
6.974 × 10⁹⁶(97-digit number)
69743239179388734492…22620383328633123841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.394 × 10⁹⁷(98-digit number)
13948647835877746898…45240766657266247681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.789 × 10⁹⁷(98-digit number)
27897295671755493796…90481533314532495361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.579 × 10⁹⁷(98-digit number)
55794591343510987593…80963066629064990721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.115 × 10⁹⁸(99-digit number)
11158918268702197518…61926133258129981441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.231 × 10⁹⁸(99-digit number)
22317836537404395037…23852266516259962881
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:57,726,210 XPM·at block #6,810,266 · updates every 60s
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