Home/Chain Registry/Block #473,368

Block #473,368

2CCLength 10ā˜…ā˜…ā˜†ā˜†ā˜†

Cunningham Chain of the Second Kind Ā· Discovered 4/3/2014, 8:40:10 PM Ā· Difficulty 10.4467 Ā· 6,323,114 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
074bf39cfe81de4c619afd03c495ae372636d2cb3449a4151a9deafa26711f8f

Height

#473,368

Difficulty

10.446744

Transactions

3

Size

645 B

Version

2

Bits

0a725dcb

Nonce

504,695

Timestamp

4/3/2014, 8:40:10 PM

Confirmations

6,323,114

Merkle Root

b6a0a74a8826bb764797dde45b2586224515b88b581f3fb95c855d38a0d5459b
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.

3.097 Ɨ 10⁹⁓(95-digit number)
30974313714462491926…34972895586138988880
Discovered Prime Numbers
p_k = 2^k Ɨ 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
3.097 Ɨ 10⁹⁓(95-digit number)
30974313714462491926…34972895586138988881
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2āˆ’1 →
2
2^1 Ɨ origin + 1
6.194 Ɨ 10⁹⁓(95-digit number)
61948627428924983852…69945791172277977761
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2āˆ’1 →
3
2^2 Ɨ origin + 1
1.238 Ɨ 10⁹⁵(96-digit number)
12389725485784996770…39891582344555955521
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2āˆ’1 →
4
2^3 Ɨ origin + 1
2.477 Ɨ 10⁹⁵(96-digit number)
24779450971569993541…79783164689111911041
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2āˆ’1 →
5
2^4 Ɨ origin + 1
4.955 Ɨ 10⁹⁵(96-digit number)
49558901943139987082…59566329378223822081
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2āˆ’1 →
6
2^5 Ɨ origin + 1
9.911 Ɨ 10⁹⁵(96-digit number)
99117803886279974164…19132658756447644161
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2āˆ’1 →
7
2^6 Ɨ origin + 1
1.982 Ɨ 10⁹⁶(97-digit number)
19823560777255994832…38265317512895288321
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2āˆ’1 →
8
2^7 Ɨ origin + 1
3.964 Ɨ 10⁹⁶(97-digit number)
39647121554511989665…76530635025790576641
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2āˆ’1 →
9
2^8 Ɨ origin + 1
7.929 Ɨ 10⁹⁶(97-digit number)
79294243109023979331…53061270051581153281
Verify on FactorDB ↗Wolfram Alpha ↗
Ɨ2āˆ’1 →
10
2^9 Ɨ origin + 1
1.585 Ɨ 10⁹⁷(98-digit number)
15858848621804795866…06122540103162306561
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 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 →
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 2CC formula:

2CC: p₁ (first prime), pā‚‚ = 2p₁ āˆ’ 1, pā‚ƒ = 2pā‚‚ āˆ’ 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 473368

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 074bf39cfe81de4c619afd03c495ae372636d2cb3449a4151a9deafa26711f8f

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 #473,368 on Chainz ↗
Circulating Supply:57,615,856 XPMĀ·at block #6,796,481 Ā· updates every 60s
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