Home/Chain Registry/Block #2,913,199

Block #2,913,199

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 11/7/2018, 4:00:06 AM · Difficulty 11.4973 · 3,920,038 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
bbdee01f99b68d12701a0a8cf646376f3a75ee1e567fbde3974f60f05f3f07fb

Difficulty

11.497309

Transactions

6

Size

1.30 KB

Version

2

Bits

0b7f4faa

Nonce

954,253,760

Timestamp

11/7/2018, 4:00:06 AM

Confirmations

3,920,038

Merkle Root

4c877a58c2ed9069e8152c0a3b288378a39dfafc49751cef82feb45864e85100
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.

3.480 × 10⁹³(94-digit number)
34803804486579233064…38821914244189150440
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
3.480 × 10⁹³(94-digit number)
34803804486579233064…38821914244189150439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
6.960 × 10⁹³(94-digit number)
69607608973158466128…77643828488378300879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.392 × 10⁹⁴(95-digit number)
13921521794631693225…55287656976756601759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.784 × 10⁹⁴(95-digit number)
27843043589263386451…10575313953513203519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.568 × 10⁹⁴(95-digit number)
55686087178526772903…21150627907026407039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.113 × 10⁹⁵(96-digit number)
11137217435705354580…42301255814052814079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.227 × 10⁹⁵(96-digit number)
22274434871410709161…84602511628105628159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.454 × 10⁹⁵(96-digit number)
44548869742821418322…69205023256211256319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
8.909 × 10⁹⁵(96-digit number)
89097739485642836645…38410046512422512639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.781 × 10⁹⁶(97-digit number)
17819547897128567329…76820093024845025279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
3.563 × 10⁹⁶(97-digit number)
35639095794257134658…53640186049690050559
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 2913199

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 bbdee01f99b68d12701a0a8cf646376f3a75ee1e567fbde3974f60f05f3f07fb

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 #2,913,199 on Chainz ↗
Circulating Supply:57,910,083 XPM·at block #6,833,236 · updates every 60s
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