Home/Chain Registry/Block #396,833

Block #396,833

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 2/9/2014, 4:06:01 PM · Difficulty 10.4158 · 6,398,069 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
223f3304be2b5fa091e34f1a1e84c8dc3ff6bd8ba30f6b37d0b0f28480e8f4d2

Height

#396,833

Difficulty

10.415837

Transactions

8

Size

2.96 KB

Version

2

Bits

0a6a7444

Nonce

145,030

Timestamp

2/9/2014, 4:06:01 PM

Confirmations

6,398,069

Merkle Root

adbfd0edbc9769531f6f11a4ab64033a184ba0a7d4f59f4ea4ffeea096ee2752
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.

1.626 × 10⁹⁹(100-digit number)
16262667194509228088…92779012578587402240
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
1.626 × 10⁹⁹(100-digit number)
16262667194509228088…92779012578587402239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.252 × 10⁹⁹(100-digit number)
32525334389018456177…85558025157174804479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
6.505 × 10⁹⁹(100-digit number)
65050668778036912354…71116050314349608959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.301 × 10¹⁰⁰(101-digit number)
13010133755607382470…42232100628699217919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.602 × 10¹⁰⁰(101-digit number)
26020267511214764941…84464201257398435839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
5.204 × 10¹⁰⁰(101-digit number)
52040535022429529883…68928402514796871679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.040 × 10¹⁰¹(102-digit number)
10408107004485905976…37856805029593743359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.081 × 10¹⁰¹(102-digit number)
20816214008971811953…75713610059187486719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
4.163 × 10¹⁰¹(102-digit number)
41632428017943623906…51427220118374973439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
8.326 × 10¹⁰¹(102-digit number)
83264856035887247813…02854440236749946879
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 First 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 1CC formula:

1CC: 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 396833

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 223f3304be2b5fa091e34f1a1e84c8dc3ff6bd8ba30f6b37d0b0f28480e8f4d2

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 #396,833 on Chainz ↗
Circulating Supply:57,603,254 XPM·at block #6,794,901 · updates every 60s
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