Home/Chain Registry/Block #365,285

Block #365,285

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/18/2014, 3:42:37 PM · Difficulty 10.4238 · 6,428,916 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
4d41f1593187520db6b0c0217e9ba08f3804bb1d34d315d16b92172a6ebdf69b

Height

#365,285

Difficulty

10.423804

Transactions

8

Size

10.62 KB

Version

2

Bits

0a6c7e69

Nonce

17,865

Timestamp

1/18/2014, 3:42:37 PM

Confirmations

6,428,916

Merkle Root

23216647d0a46538cfae6ae6cb47a059b422ed69f080f7e10c3665226d79989d
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.

1.096 × 10⁹⁴(95-digit number)
10964674514239667824…13942485408565849600
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
1.096 × 10⁹⁴(95-digit number)
10964674514239667824…13942485408565849601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.192 × 10⁹⁴(95-digit number)
21929349028479335648…27884970817131699201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.385 × 10⁹⁴(95-digit number)
43858698056958671296…55769941634263398401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.771 × 10⁹⁴(95-digit number)
87717396113917342592…11539883268526796801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.754 × 10⁹⁵(96-digit number)
17543479222783468518…23079766537053593601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.508 × 10⁹⁵(96-digit number)
35086958445566937037…46159533074107187201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.017 × 10⁹⁵(96-digit number)
70173916891133874074…92319066148214374401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.403 × 10⁹⁶(97-digit number)
14034783378226774814…84638132296428748801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.806 × 10⁹⁶(97-digit number)
28069566756453549629…69276264592857497601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.613 × 10⁹⁶(97-digit number)
56139133512907099259…38552529185714995201
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 365285

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 4d41f1593187520db6b0c0217e9ba08f3804bb1d34d315d16b92172a6ebdf69b

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 #365,285 on Chainz ↗
Circulating Supply:57,597,633 XPM·at block #6,794,200 · updates every 60s
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