Home/Chain Registry/Block #417,406

Block #417,406

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 2/24/2014, 3:48:41 AM · Difficulty 10.3910 · 6,374,385 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
d84006cc38e989aff9bf69de2e6485a88efd530d22164aad8b660a384d2728f6

Height

#417,406

Difficulty

10.390997

Transactions

1

Size

968 B

Version

2

Bits

0a64185c

Nonce

767,647

Timestamp

2/24/2014, 3:48:41 AM

Confirmations

6,374,385

Merkle Root

e204cfa9ae5853cc7fce1d6b58fc1f6ede707373dc0ba4e11c12a00baab63ca9
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.

8.298 × 10⁹¹(92-digit number)
82983245337818935526…20942753125399168000
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
8.298 × 10⁹¹(92-digit number)
82983245337818935526…20942753125399167999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.659 × 10⁹²(93-digit number)
16596649067563787105…41885506250798335999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.319 × 10⁹²(93-digit number)
33193298135127574210…83771012501596671999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
6.638 × 10⁹²(93-digit number)
66386596270255148421…67542025003193343999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.327 × 10⁹³(94-digit number)
13277319254051029684…35084050006386687999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.655 × 10⁹³(94-digit number)
26554638508102059368…70168100012773375999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.310 × 10⁹³(94-digit number)
53109277016204118737…40336200025546751999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.062 × 10⁹⁴(95-digit number)
10621855403240823747…80672400051093503999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.124 × 10⁹⁴(95-digit number)
21243710806481647494…61344800102187007999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.248 × 10⁹⁴(95-digit number)
42487421612963294989…22689600204374015999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
8.497 × 10⁹⁴(95-digit number)
84974843225926589979…45379200408748031999
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11
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 417406

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 d84006cc38e989aff9bf69de2e6485a88efd530d22164aad8b660a384d2728f6

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 #417,406 on Chainz ↗
Circulating Supply:57,578,271 XPM·at block #6,791,790 · updates every 60s
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