Home/Chain Registry/Block #2,944,145

Block #2,944,145

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 11/29/2018, 7:10:48 AM · Difficulty 11.3971 · 3,897,942 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
28dcf89dcc19fc08adcecbd37c6b40cb81bb92bd4d20f47016b30ee4348af362

Difficulty

11.397052

Transactions

6

Size

1.85 KB

Version

2

Bits

0b65a539

Nonce

1,341,352,562

Timestamp

11/29/2018, 7:10:48 AM

Confirmations

3,897,942

Merkle Root

7e1f0662fd728dc2eadef89dbb80b838c0a522469e45a02c61eff0d6993f553c
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.

1.455 × 10⁹⁵(96-digit number)
14550364214470841527…57583682531440610980
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
1.455 × 10⁹⁵(96-digit number)
14550364214470841527…57583682531440610981
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.910 × 10⁹⁵(96-digit number)
29100728428941683055…15167365062881221961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.820 × 10⁹⁵(96-digit number)
58201456857883366111…30334730125762443921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.164 × 10⁹⁶(97-digit number)
11640291371576673222…60669460251524887841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.328 × 10⁹⁶(97-digit number)
23280582743153346444…21338920503049775681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.656 × 10⁹⁶(97-digit number)
46561165486306692889…42677841006099551361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
9.312 × 10⁹⁶(97-digit number)
93122330972613385778…85355682012199102721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.862 × 10⁹⁷(98-digit number)
18624466194522677155…70711364024398205441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.724 × 10⁹⁷(98-digit number)
37248932389045354311…41422728048796410881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
7.449 × 10⁹⁷(98-digit number)
74497864778090708622…82845456097592821761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
1.489 × 10⁹⁸(99-digit number)
14899572955618141724…65690912195185643521
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 2944145

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 28dcf89dcc19fc08adcecbd37c6b40cb81bb92bd4d20f47016b30ee4348af362

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 #2,944,145 on Chainz ↗
Circulating Supply:57,981,081 XPM·at block #6,842,086 · updates every 60s
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