Home/Chain Registry/Block #2,826,910

Block #2,826,910

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 9/6/2018, 6:50:02 AM · Difficulty 11.7100 · 4,010,422 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
67408e48ad3bb5f31b02b330a67b7a13300a6f2b813164d2fa6bccd8de622fea

Difficulty

11.710039

Transactions

14

Size

3.06 KB

Version

2

Bits

0bb5c518

Nonce

576,046,497

Timestamp

9/6/2018, 6:50:02 AM

Confirmations

4,010,422

Merkle Root

6453a14f0d2c8510044c8d23e89c38c4f0f4335af9c0b9a86ca1f5b5edbb98d1
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.

3.065 × 10⁹³(94-digit number)
30655286359109522074…34409999950574142140
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
3.065 × 10⁹³(94-digit number)
30655286359109522074…34409999950574142139
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
6.131 × 10⁹³(94-digit number)
61310572718219044148…68819999901148284279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.226 × 10⁹⁴(95-digit number)
12262114543643808829…37639999802296568559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.452 × 10⁹⁴(95-digit number)
24524229087287617659…75279999604593137119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.904 × 10⁹⁴(95-digit number)
49048458174575235318…50559999209186274239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
9.809 × 10⁹⁴(95-digit number)
98096916349150470637…01119998418372548479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.961 × 10⁹⁵(96-digit number)
19619383269830094127…02239996836745096959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.923 × 10⁹⁵(96-digit number)
39238766539660188255…04479993673490193919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
7.847 × 10⁹⁵(96-digit number)
78477533079320376510…08959987346980387839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.569 × 10⁹⁶(97-digit number)
15695506615864075302…17919974693960775679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
3.139 × 10⁹⁶(97-digit number)
31391013231728150604…35839949387921551359
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 2826910

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 67408e48ad3bb5f31b02b330a67b7a13300a6f2b813164d2fa6bccd8de622fea

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 #2,826,910 on Chainz ↗
Circulating Supply:57,942,977 XPM·at block #6,837,331 · updates every 60s
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