Home/Chain Registry/Block #371,975

Block #371,975

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/23/2014, 6:45:29 AM · Difficulty 10.4289 · 6,422,091 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
d46fcf08c3324280a26fb4c5b4300019b461fc286b28647d351cc522b658ebff

Height

#371,975

Difficulty

10.428881

Transactions

5

Size

1.38 KB

Version

2

Bits

0a6dcb1e

Nonce

4,172

Timestamp

1/23/2014, 6:45:29 AM

Confirmations

6,422,091

Merkle Root

fc9762ca1c6010f91e9d274312dfd6ac95abc369d6fbb4858014f6cbc5b2c8ab
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.

1.115 × 10¹⁰⁰(101-digit number)
11157022354078098791…32245661981144084480
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
1.115 × 10¹⁰⁰(101-digit number)
11157022354078098791…32245661981144084481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.231 × 10¹⁰⁰(101-digit number)
22314044708156197582…64491323962288168961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.462 × 10¹⁰⁰(101-digit number)
44628089416312395165…28982647924576337921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.925 × 10¹⁰⁰(101-digit number)
89256178832624790330…57965295849152675841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.785 × 10¹⁰¹(102-digit number)
17851235766524958066…15930591698305351681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.570 × 10¹⁰¹(102-digit number)
35702471533049916132…31861183396610703361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.140 × 10¹⁰¹(102-digit number)
71404943066099832264…63722366793221406721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.428 × 10¹⁰²(103-digit number)
14280988613219966452…27444733586442813441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.856 × 10¹⁰²(103-digit number)
28561977226439932905…54889467172885626881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.712 × 10¹⁰²(103-digit number)
57123954452879865811…09778934345771253761
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 371975

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 d46fcf08c3324280a26fb4c5b4300019b461fc286b28647d351cc522b658ebff

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 #371,975 on Chainz ↗
Circulating Supply:57,596,545 XPM·at block #6,794,065 · updates every 60s
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