Home/Chain Registry/Block #418,328

Block #418,328

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 2/24/2014, 7:15:26 PM · Difficulty 10.3909 · 6,382,405 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
8ed6d88f1ed16e07c7cc73ec6c04113d3882b3ea2cdd669d33f74726c0de8d42

Height

#418,328

Difficulty

10.390897

Transactions

8

Size

2.61 KB

Version

2

Bits

0a6411ce

Nonce

164,397

Timestamp

2/24/2014, 7:15:26 PM

Confirmations

6,382,405

Merkle Root

dc7517b00a9e2e5093164d065902a3764401f5de9ec5333db3fc6e317a62a3a1
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.

1.629 × 10⁹⁶(97-digit number)
16297986423368444021…14102193217533159590
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
1.629 × 10⁹⁶(97-digit number)
16297986423368444021…14102193217533159589
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.259 × 10⁹⁶(97-digit number)
32595972846736888042…28204386435066319179
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
6.519 × 10⁹⁶(97-digit number)
65191945693473776084…56408772870132638359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.303 × 10⁹⁷(98-digit number)
13038389138694755216…12817545740265276719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.607 × 10⁹⁷(98-digit number)
26076778277389510433…25635091480530553439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
5.215 × 10⁹⁷(98-digit number)
52153556554779020867…51270182961061106879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.043 × 10⁹⁸(99-digit number)
10430711310955804173…02540365922122213759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.086 × 10⁹⁸(99-digit number)
20861422621911608347…05080731844244427519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
4.172 × 10⁹⁸(99-digit number)
41722845243823216694…10161463688488855039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
8.344 × 10⁹⁸(99-digit number)
83445690487646433388…20322927376977710079
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 418328

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 8ed6d88f1ed16e07c7cc73ec6c04113d3882b3ea2cdd669d33f74726c0de8d42

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 #418,328 on Chainz ↗
Circulating Supply:57,649,934 XPM·at block #6,800,732 · updates every 60s
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