XPM Prime Explorer symbol
XPMPrime Explorer
Home/Chain Registry/Block #224,949

Block #224,949

2CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the Second Kind Β· Discovered 10/24/2013, 3:31:29 AM Β· Difficulty 9.9368 Β· 6,619,911 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
1801e4e7102eb7e7e08fcc1f9b0526695dc8b2b03d3364cf68cb33e1ab939550
View on Chainz β†—

Height

#224,949

Difficulty

9.936811

Transactions

1

Size

197 B

Version

2

Bits

09efd2d6

Nonce

19,771

Timestamp

10/24/2013, 3:31:29 AM

Confirmations

6,619,911

Merkle Root

f6557aae892f391d1dc888e8ddd0eed56be7e37511367115803e8ac18528fc68
Transactions (1)
Coinbasef6557aae892f39…3e8ac18528fc68
1 in β†’ 1 out10.1100 XPM109 B
AUPukKT6…gsEb1pcY
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) β€” it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

2.570 Γ— 10⁹⁰(91-digit number)
25709128238967621064…53277278994523636880
Discovered Prime Numbers
p_k = 2^k Γ— 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
2.570 Γ— 10⁹⁰(91-digit number)
25709128238967621064…53277278994523636881
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
2
2^1 Γ— origin + 1
5.141 Γ— 10⁹⁰(91-digit number)
51418256477935242129…06554557989047273761
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
3
2^2 Γ— origin + 1
1.028 Γ— 10⁹¹(92-digit number)
10283651295587048425…13109115978094547521
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
4
2^3 Γ— origin + 1
2.056 Γ— 10⁹¹(92-digit number)
20567302591174096851…26218231956189095041
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
5
2^4 Γ— origin + 1
4.113 Γ— 10⁹¹(92-digit number)
41134605182348193703…52436463912378190081
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
6
2^5 Γ— origin + 1
8.226 Γ— 10⁹¹(92-digit number)
82269210364696387406…04872927824756380161
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
7
2^6 Γ— origin + 1
1.645 Γ— 10⁹²(93-digit number)
16453842072939277481…09745855649512760321
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
8
2^7 Γ— origin + 1
3.290 Γ— 10⁹²(93-digit number)
32907684145878554962…19491711299025520641
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
9
2^8 Γ— origin + 1
6.581 Γ— 10⁹²(93-digit number)
65815368291757109925…38983422598051041281
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
10
2^9 Γ— origin + 1
1.316 Γ— 10⁹³(94-digit number)
13163073658351421985…77966845196102082561
Verify on FactorDB β†—Wolfram Alpha β†—

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 β€” the large number shown above β€” 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 β†’
β˜…β˜…β˜†β˜†β˜†
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 Γ— 3 Γ— 5 Γ— 7 Γ— …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial β€” that divisibility is part of the proof.

Prime Chain Origin = First Prime Γ— Primorial (2Β·3Β·5Β·7Β·11·…)
Source: Primecoin prime.cpp β€” CheckPrimeProofOfWork()

This is why the origin has many small prime factors β€” those factors are the primorial divisor. The chain then extends from the first prime using the 2CC formula:

2CC: p₁ (first prime), pβ‚‚ = 2p₁ βˆ’ 1, p₃ = 2pβ‚‚ βˆ’ 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 224949

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 1801e4e7102eb7e7e08fcc1f9b0526695dc8b2b03d3364cf68cb33e1ab939550

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 β†’ Debug Window β†’ 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 #224,949 on Chainz β†—
Circulating Supply:58,003,292 XPMΒ·at block #6,844,859 Β· updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.
Privacy PolicyΒ·
AQZeJoQ81VgeHQBpEYTgvNqV1gnz3L5SvK

Cookie Preferences

We use cookies to enhance your experience. Some are essential for the site to function, while others help us understand how you use the site.

Β·Privacy Policy