Home/Chain Registry/Block #323,732

Block #323,732

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/21/2013, 8:35:29 PM · Difficulty 10.2058 · 6,491,184 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
8daba78550c22552711fe9f70531c03292b8e7babb242fc55e4bb3d36ca868ec

Height

#323,732

Difficulty

10.205812

Transactions

25

Size

6.56 KB

Version

2

Bits

0a34b013

Nonce

25,380

Timestamp

12/21/2013, 8:35:29 PM

Confirmations

6,491,184

Merkle Root

f6cbecdfde004f7f32cdd95f63e2da5c301b4e5174b51d1fca49885d3488d3b3
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.

9.576 × 10⁹⁷(98-digit number)
95767985451591762488…51564149142879948140
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
9.576 × 10⁹⁷(98-digit number)
95767985451591762488…51564149142879948141
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.915 × 10⁹⁸(99-digit number)
19153597090318352497…03128298285759896281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.830 × 10⁹⁸(99-digit number)
38307194180636704995…06256596571519792561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
7.661 × 10⁹⁸(99-digit number)
76614388361273409990…12513193143039585121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.532 × 10⁹⁹(100-digit number)
15322877672254681998…25026386286079170241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.064 × 10⁹⁹(100-digit number)
30645755344509363996…50052772572158340481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
6.129 × 10⁹⁹(100-digit number)
61291510689018727992…00105545144316680961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.225 × 10¹⁰⁰(101-digit number)
12258302137803745598…00211090288633361921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.451 × 10¹⁰⁰(101-digit number)
24516604275607491197…00422180577266723841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.903 × 10¹⁰⁰(101-digit number)
49033208551214982394…00844361154533447681
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.

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 2CC formula:

2CC: 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 323732

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 8daba78550c22552711fe9f70531c03292b8e7babb242fc55e4bb3d36ca868ec

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 #323,732 on Chainz ↗
Circulating Supply:57,763,420 XPM·at block #6,814,915 · updates every 60s
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