Home/Chain Registry/Block #450,689

Block #450,689

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/19/2014, 11:05:54 AM · Difficulty 10.3747 · 6,344,825 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
db4feeee1b6dd00c5678bc27929cec6f30ed74929cf3262d8553ed75b5fddee0

Height

#450,689

Difficulty

10.374730

Transactions

6

Size

2.08 KB

Version

2

Bits

0a5fee55

Nonce

26,329,154

Timestamp

3/19/2014, 11:05:54 AM

Confirmations

6,344,825

Merkle Root

fd013f9d96245735f81ed793afba21dba37e1a3e1fbad596682172c26ea8a00b
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.

1.995 × 10⁹⁵(96-digit number)
19954857384298348596…28461136468750403200
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
1.995 × 10⁹⁵(96-digit number)
19954857384298348596…28461136468750403199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.990 × 10⁹⁵(96-digit number)
39909714768596697193…56922272937500806399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
7.981 × 10⁹⁵(96-digit number)
79819429537193394386…13844545875001612799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.596 × 10⁹⁶(97-digit number)
15963885907438678877…27689091750003225599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.192 × 10⁹⁶(97-digit number)
31927771814877357754…55378183500006451199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.385 × 10⁹⁶(97-digit number)
63855543629754715509…10756367000012902399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.277 × 10⁹⁷(98-digit number)
12771108725950943101…21512734000025804799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.554 × 10⁹⁷(98-digit number)
25542217451901886203…43025468000051609599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.108 × 10⁹⁷(98-digit number)
51084434903803772407…86050936000103219199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.021 × 10⁹⁸(99-digit number)
10216886980760754481…72101872000206438399
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 450689

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 db4feeee1b6dd00c5678bc27929cec6f30ed74929cf3262d8553ed75b5fddee0

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 #450,689 on Chainz ↗
Circulating Supply:57,608,175 XPM·at block #6,795,513 · updates every 60s
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