Home/Chain Registry/Block #2,049,418

Block #2,049,418

1CCLength 10ā˜…ā˜…ā˜†ā˜†ā˜†

Cunningham Chain of the First Kind Ā· Discovered 4/2/2017, 8:47:23 AM Ā· Difficulty 10.6941 Ā· 4,789,040 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
2168629f722902ca3e383ed120e8ad0968694a727a7efd69ba05e7385a2ee5e5

Difficulty

10.694081

Transactions

4

Size

1.13 KB

Version

2

Bits

0ab1af48

Nonce

1,676,856,143

Timestamp

4/2/2017, 8:47:23 AM

Confirmations

4,789,040

Merkle Root

f16cb8c9e0a4af9a450f9a3258917e4f91bcf6542168bb4741906885bcb72d58
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.

2.773 Ɨ 10⁹⁓(95-digit number)
27739505514039135514…94214459269312585400
Discovered Prime Numbers
p_k = 2^k Ɨ origin āˆ’ 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 āˆ’ 1
2.773 Ɨ 10⁹⁓(95-digit number)
27739505514039135514…94214459269312585399
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
2
2^1 Ɨ origin āˆ’ 1
5.547 Ɨ 10⁹⁓(95-digit number)
55479011028078271029…88428918538625170799
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
3
2^2 Ɨ origin āˆ’ 1
1.109 Ɨ 10⁹⁵(96-digit number)
11095802205615654205…76857837077250341599
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
4
2^3 Ɨ origin āˆ’ 1
2.219 Ɨ 10⁹⁵(96-digit number)
22191604411231308411…53715674154500683199
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
5
2^4 Ɨ origin āˆ’ 1
4.438 Ɨ 10⁹⁵(96-digit number)
44383208822462616823…07431348309001366399
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
6
2^5 Ɨ origin āˆ’ 1
8.876 Ɨ 10⁹⁵(96-digit number)
88766417644925233646…14862696618002732799
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
7
2^6 Ɨ origin āˆ’ 1
1.775 Ɨ 10⁹⁶(97-digit number)
17753283528985046729…29725393236005465599
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
8
2^7 Ɨ origin āˆ’ 1
3.550 Ɨ 10⁹⁶(97-digit number)
35506567057970093458…59450786472010931199
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
9
2^8 Ɨ origin āˆ’ 1
7.101 Ɨ 10⁹⁶(97-digit number)
71013134115940186917…18901572944021862399
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2+1 →
10
2^9 Ɨ origin āˆ’ 1
1.420 Ɨ 10⁹⁷(98-digit number)
14202626823188037383…37803145888043724799
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 10 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 →
ā˜…ā˜…ā˜†ā˜†ā˜†
Rarity
UncommonChain length 10
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 Ɨ 3 Ɨ 5 Ɨ 7 Ɨ …), 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 Ɨ Primorial (2Ā·3Ā·5Ā·7Ā·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), pā‚‚ = 2p₁ + 1, pā‚ƒ = 2pā‚‚ + 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 2049418

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 2168629f722902ca3e383ed120e8ad0968694a727a7efd69ba05e7385a2ee5e5

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 #2,049,418 on Chainz ↗
Circulating Supply:57,951,942 XPMĀ·at block #6,838,457 Ā· updates every 60s
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