Home/Chain Registry/Block #2,924,926

Block #2,924,926

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 11/16/2018, 4:19:52 AM · Difficulty 11.3560 · 3,913,720 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
0ec394708daaddd7f3813d0dec274643470bbd6e9ab4287d58dcd29861911b40

Difficulty

11.356013

Transactions

11

Size

72.91 KB

Version

2

Bits

0b5b23aa

Nonce

19,596,258

Timestamp

11/16/2018, 4:19:52 AM

Confirmations

3,913,720

Merkle Root

a7390aee82757421ab96f1f1d3d83efb99934cf678be06d84a1ad2a2dab17266
Transactions (11)
1 in → 1 out8.5400 XPM110 B
50 in → 1 out235.7441 XPM7.27 KB
50 in → 1 out230.2390 XPM7.27 KB
50 in → 1 out235.9153 XPM7.27 KB
50 in → 1 out240.3145 XPM7.27 KB
50 in → 1 out225.3261 XPM7.27 KB
50 in → 1 out232.5443 XPM7.27 KB
50 in → 1 out213.1693 XPM7.27 KB
50 in → 1 out244.0100 XPM7.27 KB
50 in → 1 out219.6015 XPM7.28 KB
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.

6.136 × 10⁹⁴(95-digit number)
61368740275657467345…89277936172040709920
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
6.136 × 10⁹⁴(95-digit number)
61368740275657467345…89277936172040709921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.227 × 10⁹⁵(96-digit number)
12273748055131493469…78555872344081419841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.454 × 10⁹⁵(96-digit number)
24547496110262986938…57111744688162839681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.909 × 10⁹⁵(96-digit number)
49094992220525973876…14223489376325679361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
9.818 × 10⁹⁵(96-digit number)
98189984441051947753…28446978752651358721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.963 × 10⁹⁶(97-digit number)
19637996888210389550…56893957505302717441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.927 × 10⁹⁶(97-digit number)
39275993776420779101…13787915010605434881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
7.855 × 10⁹⁶(97-digit number)
78551987552841558202…27575830021210869761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.571 × 10⁹⁷(98-digit number)
15710397510568311640…55151660042421739521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.142 × 10⁹⁷(98-digit number)
31420795021136623281…10303320084843479041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
6.284 × 10⁹⁷(98-digit number)
62841590042273246562…20606640169686958081
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 2924926

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 0ec394708daaddd7f3813d0dec274643470bbd6e9ab4287d58dcd29861911b40

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 #2,924,926 on Chainz ↗
Circulating Supply:57,953,433 XPM·at block #6,838,645 · updates every 60s
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