Home/Chain Registry/Block #326,884

Block #326,884

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/24/2013, 3:44:52 AM · Difficulty 10.1811 · 6,464,871 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
ffaad91249fffc9120453d6f4e1cb0481c422ef3b90fe023535b714b5a5338cc

Height

#326,884

Difficulty

10.181121

Transactions

10

Size

2.62 KB

Version

2

Bits

0a2e5df2

Nonce

276,195

Timestamp

12/24/2013, 3:44:52 AM

Confirmations

6,464,871

Merkle Root

b81714e2f84f699a69c06a846d374c2be44851736ce87e72bb9e12dbcc9c0cbd
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.

5.688 × 10⁹⁶(97-digit number)
56887122893585150188…33022697197241768700
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
5.688 × 10⁹⁶(97-digit number)
56887122893585150188…33022697197241768699
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.137 × 10⁹⁷(98-digit number)
11377424578717030037…66045394394483537399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.275 × 10⁹⁷(98-digit number)
22754849157434060075…32090788788967074799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.550 × 10⁹⁷(98-digit number)
45509698314868120150…64181577577934149599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
9.101 × 10⁹⁷(98-digit number)
91019396629736240301…28363155155868299199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.820 × 10⁹⁸(99-digit number)
18203879325947248060…56726310311736598399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.640 × 10⁹⁸(99-digit number)
36407758651894496120…13452620623473196799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
7.281 × 10⁹⁸(99-digit number)
72815517303788992241…26905241246946393599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.456 × 10⁹⁹(100-digit number)
14563103460757798448…53810482493892787199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.912 × 10⁹⁹(100-digit number)
29126206921515596896…07620964987785574399
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 First 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.

View full Prime Chain Discovery page →
★★☆☆☆
Rarity
UncommonChain length 10
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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Verify on a Primecoin Node

Anyone running a Primecoin node can independently verify this block using the following RPC commands. Run these from the primecoin-cli command line or via the debug console in the Primecoin wallet.

1. Get block hash by height
getblockhash 326884

Returns the block hash for a given block height. Use this to confirm the hash shown above matches the chain.

2. Get full block data
getblock ffaad91249fffc9120453d6f4e1cb0481c422ef3b90fe023535b714b5a5338cc

Returns the full block header including difficulty, prime chain origin, prime chain type, transaction IDs, and all other fields shown on this page.

How to run these commands: To verify this data independently, open a terminal on your own Primecoin node and run primecoin-cli <command>. Alternatively, open the Primecoin-Qt wallet, go to Help → Debug Window → Console, and type the command directly. The node must be fully synced to this block height for the commands to return results.

Cross-reference on Chainz Explorer

Chainz is an independent Primecoin block explorer. Compare this block's data to verify accuracy.

View Block #326,884 on Chainz ↗
Circulating Supply:57,577,985 XPM·at block #6,791,754 · 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.