Home/Chain Registry/Block #2,864,414

Block #2,864,414

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 10/2/2018, 6:34:13 PM · Difficulty 11.6722 · 3,969,004 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
c22cb393ce5a1b8044776ff9b4b47cc366ac716eb55565981700b4cc192ebf0c

Difficulty

11.672210

Transactions

8

Size

1.72 KB

Version

2

Bits

0bac15f3

Nonce

447,825,705

Timestamp

10/2/2018, 6:34:13 PM

Confirmations

3,969,004

Merkle Root

0c7cc762766227727a5da949c72aff819e98ff0c82452fdd32d8706abb89861f
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.

1.382 × 10⁹⁴(95-digit number)
13824455136435076646…12380967460710418080
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
1.382 × 10⁹⁴(95-digit number)
13824455136435076646…12380967460710418081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.764 × 10⁹⁴(95-digit number)
27648910272870153293…24761934921420836161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.529 × 10⁹⁴(95-digit number)
55297820545740306586…49523869842841672321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.105 × 10⁹⁵(96-digit number)
11059564109148061317…99047739685683344641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.211 × 10⁹⁵(96-digit number)
22119128218296122634…98095479371366689281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.423 × 10⁹⁵(96-digit number)
44238256436592245269…96190958742733378561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
8.847 × 10⁹⁵(96-digit number)
88476512873184490538…92381917485466757121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.769 × 10⁹⁶(97-digit number)
17695302574636898107…84763834970933514241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.539 × 10⁹⁶(97-digit number)
35390605149273796215…69527669941867028481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
7.078 × 10⁹⁶(97-digit number)
70781210298547592430…39055339883734056961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
1.415 × 10⁹⁷(98-digit number)
14156242059709518486…78110679767468113921
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 Second 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 2CC formula:

2CC: 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 2864414

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 c22cb393ce5a1b8044776ff9b4b47cc366ac716eb55565981700b4cc192ebf0c

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 #2,864,414 on Chainz ↗
Circulating Supply:57,911,547 XPM·at block #6,833,417 · updates every 60s
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