Home/Chain Registry/Block #328,035

Block #328,035

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/24/2013, 11:45:53 PM · Difficulty 10.1732 · 6,465,213 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
c5be03bb7f51e6e3ad1ad07a9591a4e7af95f9f657aca87b06e1586f71b06734

Height

#328,035

Difficulty

10.173191

Transactions

8

Size

2.83 KB

Version

2

Bits

0a2c563c

Nonce

266,998

Timestamp

12/24/2013, 11:45:53 PM

Confirmations

6,465,213

Merkle Root

0b61e33d8ace1163a5da72f8fe14346c50054f51c325b043f761763d050bf02e
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.

1.493 × 10⁹⁷(98-digit number)
14933393780518773480…16595525746099250480
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
1.493 × 10⁹⁷(98-digit number)
14933393780518773480…16595525746099250481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.986 × 10⁹⁷(98-digit number)
29866787561037546960…33191051492198500961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.973 × 10⁹⁷(98-digit number)
59733575122075093920…66382102984397001921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.194 × 10⁹⁸(99-digit number)
11946715024415018784…32764205968794003841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.389 × 10⁹⁸(99-digit number)
23893430048830037568…65528411937588007681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.778 × 10⁹⁸(99-digit number)
47786860097660075136…31056823875176015361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
9.557 × 10⁹⁸(99-digit number)
95573720195320150272…62113647750352030721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.911 × 10⁹⁹(100-digit number)
19114744039064030054…24227295500704061441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.822 × 10⁹⁹(100-digit number)
38229488078128060108…48454591001408122881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
7.645 × 10⁹⁹(100-digit number)
76458976156256120217…96909182002816245761
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 328035

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 c5be03bb7f51e6e3ad1ad07a9591a4e7af95f9f657aca87b06e1586f71b06734

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 #328,035 on Chainz ↗
Circulating Supply:57,589,985 XPM·at block #6,793,247 · updates every 60s
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