Home/Chain Registry/Block #2,924,966

Block #2,924,966

2CCLength 12★★★★☆

Cunningham Chain of the Second Kind · Discovered 11/16/2018, 4:53:58 AM · Difficulty 11.3565 · 3,918,837 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
b69aabbf4dceccd05d1314abb3490c951b490c94c947457040f6d0d52ec92f71

Difficulty

11.356483

Transactions

7

Size

43.80 KB

Version

2

Bits

0b5b4275

Nonce

329,783,050

Timestamp

11/16/2018, 4:53:58 AM

Confirmations

3,918,837

Merkle Root

0d1a894a65ff5143f345c768bdc34cba5a44a48dc0f46dee07c3f6c2cfa87277
Transactions (7)
1 in → 1 out8.2200 XPM110 B
50 in → 1 out241.0363 XPM7.27 KB
50 in → 1 out209.7405 XPM7.27 KB
50 in → 1 out239.7618 XPM7.27 KB
50 in → 1 out230.8867 XPM7.27 KB
50 in → 1 out238.7940 XPM7.26 KB
50 in → 1 out214.4799 XPM7.26 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.

2.590 × 10⁹⁶(97-digit number)
25902526386830262736…00999025637255307520
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
2.590 × 10⁹⁶(97-digit number)
25902526386830262736…00999025637255307521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.180 × 10⁹⁶(97-digit number)
51805052773660525473…01998051274510615041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.036 × 10⁹⁷(98-digit number)
10361010554732105094…03996102549021230081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.072 × 10⁹⁷(98-digit number)
20722021109464210189…07992205098042460161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.144 × 10⁹⁷(98-digit number)
41444042218928420378…15984410196084920321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
8.288 × 10⁹⁷(98-digit number)
82888084437856840757…31968820392169840641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.657 × 10⁹⁸(99-digit number)
16577616887571368151…63937640784339681281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.315 × 10⁹⁸(99-digit number)
33155233775142736303…27875281568679362561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.631 × 10⁹⁸(99-digit number)
66310467550285472606…55750563137358725121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.326 × 10⁹⁹(100-digit number)
13262093510057094521…11501126274717450241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
2.652 × 10⁹⁹(100-digit number)
26524187020114189042…23002252549434900481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
12
2^11 × origin + 1
5.304 × 10⁹⁹(100-digit number)
53048374040228378085…46004505098869800961
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 12 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
ExceptionalChain length 12
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 2924966

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 b69aabbf4dceccd05d1314abb3490c951b490c94c947457040f6d0d52ec92f71

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 #2,924,966 on Chainz ↗
Circulating Supply:57,994,801 XPM·at block #6,843,802 · updates every 60s
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