Home/Chain Registry/Block #322,298

Block #322,298

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/20/2013, 9:39:30 PM · Difficulty 10.1962 · 6,476,254 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
7dc053c3db8925f399fbbfb75120d0faf524898f94565c335765488e792cdecf

Height

#322,298

Difficulty

10.196174

Transactions

8

Size

2.70 KB

Version

2

Bits

0a32387b

Nonce

117,390

Timestamp

12/20/2013, 9:39:30 PM

Confirmations

6,476,254

Merkle Root

15a1a8489ddae18638df274eb988707b5b7bf6513320fc2020586df8e2c2d28b
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.

1.627 × 10⁹⁵(96-digit number)
16274715412910824260…67951169088765220040
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
1.627 × 10⁹⁵(96-digit number)
16274715412910824260…67951169088765220041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.254 × 10⁹⁵(96-digit number)
32549430825821648521…35902338177530440081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
6.509 × 10⁹⁵(96-digit number)
65098861651643297042…71804676355060880161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.301 × 10⁹⁶(97-digit number)
13019772330328659408…43609352710121760321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.603 × 10⁹⁶(97-digit number)
26039544660657318816…87218705420243520641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.207 × 10⁹⁶(97-digit number)
52079089321314637633…74437410840487041281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.041 × 10⁹⁷(98-digit number)
10415817864262927526…48874821680974082561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.083 × 10⁹⁷(98-digit number)
20831635728525855053…97749643361948165121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.166 × 10⁹⁷(98-digit number)
41663271457051710107…95499286723896330241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
8.332 × 10⁹⁷(98-digit number)
83326542914103420214…90998573447792660481
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 322298

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 7dc053c3db8925f399fbbfb75120d0faf524898f94565c335765488e792cdecf

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 #322,298 on Chainz ↗
Circulating Supply:57,632,431 XPM·at block #6,798,551 · updates every 60s
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