Home/Chain Registry/Block #922,297

Block #922,297

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 2/4/2015, 8:57:27 AM · Difficulty 10.9158 · 5,879,569 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
a431368115b39a5703f33c24c43da54ef820bb58d5d29d9d928f36b3b7f0402e

Height

#922,297

Difficulty

10.915762

Transactions

12

Size

318.66 KB

Version

2

Bits

0aea6f5d

Nonce

1,491,155,902

Timestamp

2/4/2015, 8:57:27 AM

Confirmations

5,879,569

Merkle Root

71a09645bf9e0a8f06188f6c67d50875769d9ebddde180b6968179ceb7a9e1bf
Transactions (12)
1 in → 1 out11.6800 XPM109 B
200 in → 1 out1049.9876 XPM28.97 KB
200 in → 1 out986.7652 XPM28.94 KB
200 in → 1 out1023.6212 XPM28.95 KB
200 in → 1 out1099.9303 XPM28.95 KB
200 in → 1 out1046.3933 XPM28.95 KB
200 in → 1 out908.2306 XPM28.95 KB
200 in → 1 out918.4583 XPM28.95 KB
200 in → 1 out1036.7281 XPM28.95 KB
200 in → 1 out933.7073 XPM28.95 KB
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.

3.354 × 10⁹⁵(96-digit number)
33540323455540424723…22899154615404789760
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
3.354 × 10⁹⁵(96-digit number)
33540323455540424723…22899154615404789761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.708 × 10⁹⁵(96-digit number)
67080646911080849446…45798309230809579521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.341 × 10⁹⁶(97-digit number)
13416129382216169889…91596618461619159041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.683 × 10⁹⁶(97-digit number)
26832258764432339778…83193236923238318081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.366 × 10⁹⁶(97-digit number)
53664517528864679557…66386473846476636161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.073 × 10⁹⁷(98-digit number)
10732903505772935911…32772947692953272321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.146 × 10⁹⁷(98-digit number)
21465807011545871822…65545895385906544641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.293 × 10⁹⁷(98-digit number)
42931614023091743645…31091790771813089281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
8.586 × 10⁹⁷(98-digit number)
85863228046183487291…62183581543626178561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.717 × 10⁹⁸(99-digit number)
17172645609236697458…24367163087252357121
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 922297

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 a431368115b39a5703f33c24c43da54ef820bb58d5d29d9d928f36b3b7f0402e

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 #922,297 on Chainz ↗
Circulating Supply:57,659,020 XPM·at block #6,801,865 · updates every 60s
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