Home/Chain Registry/Block #2,455,433

Block #2,455,433

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/3/2018, 8:36:07 AM · Difficulty 10.9527 · 4,388,607 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
0f481c5f7923b5ccd49a2c2ed4a69c3eb0a27eb84b553ebd3fffcde6f2bcaee3

Difficulty

10.952725

Transactions

45

Size

11.43 KB

Version

2

Bits

0af3e5c8

Nonce

361,831,422

Timestamp

1/3/2018, 8:36:07 AM

Confirmations

4,388,607

Merkle Root

19ce4c7a39047205881e58ec92ae30406c3580621bd2cfb0fdfb8b1a9925c791
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.

1.870 × 10⁹⁴(95-digit number)
18702093531820273791…45606958077619524480
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
1.870 × 10⁹⁴(95-digit number)
18702093531820273791…45606958077619524481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.740 × 10⁹⁴(95-digit number)
37404187063640547583…91213916155239048961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
7.480 × 10⁹⁴(95-digit number)
74808374127281095166…82427832310478097921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.496 × 10⁹⁵(96-digit number)
14961674825456219033…64855664620956195841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.992 × 10⁹⁵(96-digit number)
29923349650912438066…29711329241912391681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.984 × 10⁹⁵(96-digit number)
59846699301824876132…59422658483824783361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.196 × 10⁹⁶(97-digit number)
11969339860364975226…18845316967649566721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.393 × 10⁹⁶(97-digit number)
23938679720729950453…37690633935299133441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.787 × 10⁹⁶(97-digit number)
47877359441459900906…75381267870598266881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
9.575 × 10⁹⁶(97-digit number)
95754718882919801812…50762535741196533761
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 2455433

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 0f481c5f7923b5ccd49a2c2ed4a69c3eb0a27eb84b553ebd3fffcde6f2bcaee3

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 #2,455,433 on Chainz ↗
Circulating Supply:57,996,689 XPM·at block #6,844,039 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.
Privacy Policy·

Cookie Preferences

We use cookies to enhance your experience. Some are essential for the site to function, while others help us understand how you use the site.

·Privacy Policy