Home/Chain Registry/Block #2,862,929

Block #2,862,929

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 10/1/2018, 5:26:58 PM · Difficulty 11.6738 · 3,980,488 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
08de113edede59dd8b35f44c09229938069776922f690df8ecfadbf5f45e926b

Difficulty

11.673784

Transactions

5

Size

1.64 KB

Version

2

Bits

0bac7d1f

Nonce

1,433,836,860

Timestamp

10/1/2018, 5:26:58 PM

Confirmations

3,980,488

Merkle Root

4758be0ccda5dec5dae0dfba2a127502c08a77f05e454a571ef7b7e40a92dd26
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.

4.237 × 10⁹³(94-digit number)
42374335251430342738…00385068140919588650
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
4.237 × 10⁹³(94-digit number)
42374335251430342738…00385068140919588649
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.474 × 10⁹³(94-digit number)
84748670502860685477…00770136281839177299
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.694 × 10⁹⁴(95-digit number)
16949734100572137095…01540272563678354599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.389 × 10⁹⁴(95-digit number)
33899468201144274191…03080545127356709199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.779 × 10⁹⁴(95-digit number)
67798936402288548382…06161090254713418399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.355 × 10⁹⁵(96-digit number)
13559787280457709676…12322180509426836799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.711 × 10⁹⁵(96-digit number)
27119574560915419352…24644361018853673599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.423 × 10⁹⁵(96-digit number)
54239149121830838705…49288722037707347199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.084 × 10⁹⁶(97-digit number)
10847829824366167741…98577444075414694399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.169 × 10⁹⁶(97-digit number)
21695659648732335482…97154888150829388799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
4.339 × 10⁹⁶(97-digit number)
43391319297464670964…94309776301658777599
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 2862929

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 08de113edede59dd8b35f44c09229938069776922f690df8ecfadbf5f45e926b

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 #2,862,929 on Chainz ↗
Circulating Supply:57,991,704 XPM·at block #6,843,416 · updates every 60s
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