Home/Chain Registry/Block #2,804,448

Block #2,804,448

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 8/22/2018, 3:36:46 AM · Difficulty 11.6681 · 4,039,363 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
c504c28ec926f0173a14c58d0d6bf5538dfef7778ea5d1173083a74f9758400c

Difficulty

11.668051

Transactions

20

Size

5.98 KB

Version

2

Bits

0bab0563

Nonce

750,938,799

Timestamp

8/22/2018, 3:36:46 AM

Confirmations

4,039,363

Merkle Root

deaa9cfdcc57aaf2551cc9d4ec7cc566494a6442be4ead263534732361b6c309
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.

7.446 × 10⁹³(94-digit number)
74462927414824688787…01533343372116645000
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
7.446 × 10⁹³(94-digit number)
74462927414824688787…01533343372116644999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.489 × 10⁹⁴(95-digit number)
14892585482964937757…03066686744233289999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.978 × 10⁹⁴(95-digit number)
29785170965929875515…06133373488466579999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.957 × 10⁹⁴(95-digit number)
59570341931859751030…12266746976933159999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.191 × 10⁹⁵(96-digit number)
11914068386371950206…24533493953866319999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.382 × 10⁹⁵(96-digit number)
23828136772743900412…49066987907732639999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.765 × 10⁹⁵(96-digit number)
47656273545487800824…98133975815465279999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
9.531 × 10⁹⁵(96-digit number)
95312547090975601648…96267951630930559999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.906 × 10⁹⁶(97-digit number)
19062509418195120329…92535903261861119999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.812 × 10⁹⁶(97-digit number)
38125018836390240659…85071806523722239999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
7.625 × 10⁹⁶(97-digit number)
76250037672780481318…70143613047444479999
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 2804448

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 c504c28ec926f0173a14c58d0d6bf5538dfef7778ea5d1173083a74f9758400c

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 #2,804,448 on Chainz ↗
Circulating Supply:57,994,863 XPM·at block #6,843,810 · updates every 60s
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