Block #334,215

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/29/2013, 8:43:10 AM · Difficulty 10.1561 · 6,461,687 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
57419d6b0c59dbe2f2ffd6e31d257804cdacb2b1542d3221d788b283e32430ab

Height

#334,215

Difficulty

10.156112

Transactions

6

Size

16.04 KB

Version

2

Bits

0a27f6ee

Nonce

11,623

Timestamp

12/29/2013, 8:43:10 AM

Confirmations

6,461,687

Merkle Root

bc358dd7e8a85e7c43b8ecba1f47c928f48903b1b43b527e800bb7daf3f5ba38
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.

1.595 × 10⁹⁶(97-digit number)
15956641634399896956…19293956439190831681
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
1.595 × 10⁹⁶(97-digit number)
15956641634399896956…19293956439190831681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.191 × 10⁹⁶(97-digit number)
31913283268799793913…38587912878381663361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
6.382 × 10⁹⁶(97-digit number)
63826566537599587826…77175825756763326721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.276 × 10⁹⁷(98-digit number)
12765313307519917565…54351651513526653441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.553 × 10⁹⁷(98-digit number)
25530626615039835130…08703303027053306881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.106 × 10⁹⁷(98-digit number)
51061253230079670261…17406606054106613761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.021 × 10⁹⁸(99-digit number)
10212250646015934052…34813212108213227521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.042 × 10⁹⁸(99-digit number)
20424501292031868104…69626424216426455041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.084 × 10⁹⁸(99-digit number)
40849002584063736208…39252848432852910081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
8.169 × 10⁹⁸(99-digit number)
81698005168127472417…78505696865705820161
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:57,611,300 XPM·at block #6,795,901 · updates every 60s
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