Block #330,580

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 12/26/2013, 6:43:48 PM · Difficulty 10.1684 · 6,472,108 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
33cc9ca7b8b39bbe6bc662cf9a34a215849d96dd176111e413cc3099f78653af

Height

#330,580

Difficulty

10.168355

Transactions

1

Size

1.02 KB

Version

2

Bits

0a2b194b

Nonce

2,712

Timestamp

12/26/2013, 6:43:48 PM

Confirmations

6,472,108

Merkle Root

97679d8a2e667f9150748c22974d1218780e088db0ac598a378096569e66da3d
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.

1.937 × 10¹⁰¹(102-digit number)
19370798545971623183…20891336236040555521
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
1.937 × 10¹⁰¹(102-digit number)
19370798545971623183…20891336236040555521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.874 × 10¹⁰¹(102-digit number)
38741597091943246366…41782672472081111041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
7.748 × 10¹⁰¹(102-digit number)
77483194183886492733…83565344944162222081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.549 × 10¹⁰²(103-digit number)
15496638836777298546…67130689888324444161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.099 × 10¹⁰²(103-digit number)
30993277673554597093…34261379776648888321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
6.198 × 10¹⁰²(103-digit number)
61986555347109194186…68522759553297776641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.239 × 10¹⁰³(104-digit number)
12397311069421838837…37045519106595553281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.479 × 10¹⁰³(104-digit number)
24794622138843677674…74091038213191106561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.958 × 10¹⁰³(104-digit number)
49589244277687355349…48182076426382213121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
9.917 × 10¹⁰³(104-digit number)
99178488555374710698…96364152852764426241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
1.983 × 10¹⁰⁴(105-digit number)
19835697711074942139…92728305705528852481
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,665,526 XPM·at block #6,802,687 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.