Home/Chain Registry/Block #430,251

Block #430,251

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/5/2014, 9:21:42 AM · Difficulty 10.3417 · 6,367,715 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
2738a538a31df3c5f38b6346262ce088cc0d3009430a0bf859483aba7a7dbb97

Height

#430,251

Difficulty

10.341651

Transactions

5

Size

1.08 KB

Version

2

Bits

0a577674

Nonce

891,400

Timestamp

3/5/2014, 9:21:42 AM

Confirmations

6,367,715

Merkle Root

2bed1a33fc4684e96bec0e6eb5daca657da729937fcd80d9266667b30cdec607
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.

3.462 × 10⁹⁶(97-digit number)
34624333347598828609…07968711192445100800
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
3.462 × 10⁹⁶(97-digit number)
34624333347598828609…07968711192445100799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
6.924 × 10⁹⁶(97-digit number)
69248666695197657218…15937422384890201599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.384 × 10⁹⁷(98-digit number)
13849733339039531443…31874844769780403199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.769 × 10⁹⁷(98-digit number)
27699466678079062887…63749689539560806399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.539 × 10⁹⁷(98-digit number)
55398933356158125775…27499379079121612799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.107 × 10⁹⁸(99-digit number)
11079786671231625155…54998758158243225599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.215 × 10⁹⁸(99-digit number)
22159573342463250310…09997516316486451199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.431 × 10⁹⁸(99-digit number)
44319146684926500620…19995032632972902399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
8.863 × 10⁹⁸(99-digit number)
88638293369853001240…39990065265945804799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.772 × 10⁹⁹(100-digit number)
17727658673970600248…79980130531891609599
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 430251

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 2738a538a31df3c5f38b6346262ce088cc0d3009430a0bf859483aba7a7dbb97

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 #430,251 on Chainz ↗
Circulating Supply:57,627,719 XPM·at block #6,797,965 · updates every 60s
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