Home/Chain Registry/Block #329,450

Block #329,450

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/25/2013, 11:32:40 PM · Difficulty 10.1717 · 6,470,788 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
5ae8d272a875b8ebbad45a23ded2ac442dab6ab0bab98fc7c25902b030288708

Height

#329,450

Difficulty

10.171681

Transactions

5

Size

1.37 KB

Version

2

Bits

0a2bf346

Nonce

6,857

Timestamp

12/25/2013, 11:32:40 PM

Confirmations

6,470,788

Merkle Root

5f1373d9a72f67ab8a439505f0b8df4faeb454c5857909967dc5f4084b89a280
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.

7.482 × 10⁹⁶(97-digit number)
74826116932501844822…85713597901008155760
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
7.482 × 10⁹⁶(97-digit number)
74826116932501844822…85713597901008155761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.496 × 10⁹⁷(98-digit number)
14965223386500368964…71427195802016311521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.993 × 10⁹⁷(98-digit number)
29930446773000737929…42854391604032623041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.986 × 10⁹⁷(98-digit number)
59860893546001475858…85708783208065246081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.197 × 10⁹⁸(99-digit number)
11972178709200295171…71417566416130492161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.394 × 10⁹⁸(99-digit number)
23944357418400590343…42835132832260984321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.788 × 10⁹⁸(99-digit number)
47888714836801180686…85670265664521968641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
9.577 × 10⁹⁸(99-digit number)
95777429673602361373…71340531329043937281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.915 × 10⁹⁹(100-digit number)
19155485934720472274…42681062658087874561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.831 × 10⁹⁹(100-digit number)
38310971869440944549…85362125316175749121
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 329450

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 5ae8d272a875b8ebbad45a23ded2ac442dab6ab0bab98fc7c25902b030288708

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 #329,450 on Chainz ↗
Circulating Supply:57,645,958 XPM·at block #6,800,237 · updates every 60s
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