Home/Chain Registry/Block #365,328

Block #365,328

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/18/2014, 4:17:35 PM · Difficulty 10.4246 · 6,439,607 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
d9be0563c1a9c75cece94de9ddf60a86daa74226a0077708c9d6422d9c022e2c

Height

#365,328

Difficulty

10.424577

Transactions

9

Size

3.01 KB

Version

2

Bits

0a6cb112

Nonce

55,563

Timestamp

1/18/2014, 4:17:35 PM

Confirmations

6,439,607

Merkle Root

33ac33a6dcf43babf20d09b47e9e4f7f0df507b16964cf5c862ca18696d2e574
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.

1.606 × 10⁸⁸(89-digit number)
16067964463168974386…09831433665784609280
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
1.606 × 10⁸⁸(89-digit number)
16067964463168974386…09831433665784609281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.213 × 10⁸⁸(89-digit number)
32135928926337948773…19662867331569218561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
6.427 × 10⁸⁸(89-digit number)
64271857852675897547…39325734663138437121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.285 × 10⁸⁹(90-digit number)
12854371570535179509…78651469326276874241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.570 × 10⁸⁹(90-digit number)
25708743141070359018…57302938652553748481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.141 × 10⁸⁹(90-digit number)
51417486282140718037…14605877305107496961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.028 × 10⁹⁰(91-digit number)
10283497256428143607…29211754610214993921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.056 × 10⁹⁰(91-digit number)
20566994512856287215…58423509220429987841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.113 × 10⁹⁰(91-digit number)
41133989025712574430…16847018440859975681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
8.226 × 10⁹⁰(91-digit number)
82267978051425148860…33694036881719951361
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 365328

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 d9be0563c1a9c75cece94de9ddf60a86daa74226a0077708c9d6422d9c022e2c

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 #365,328 on Chainz ↗
Circulating Supply:57,683,554 XPM·at block #6,804,934 · updates every 60s
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