XPM Prime Explorer symbol
XPMPrime Explorer
Home/Chain Registry/Block #244,201

Block #244,201

2CCLength 9β˜…β˜†β˜†β˜†β˜†

Cunningham Chain of the Second Kind Β· Discovered 11/4/2013, 5:33:00 PM Β· Difficulty 9.9627 Β· 6,555,963 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
fc1db5bb7ce69016707d4954312dd8613fae3b87e6fb5efb2e55694fac2accb7
View on Chainz β†—

Height

#244,201

Difficulty

9.962663

Transactions

1

Size

202 B

Version

2

Bits

09f67118

Nonce

28,532

Timestamp

11/4/2013, 5:33:00 PM

Confirmations

6,555,963

Merkle Root

47a311a5b5be864f50732c577bda80bd82bb91d82672832d251881f801fe1c3b
Transactions (1)
Coinbase47a311a5b5be86…1881f801fe1c3b
1 in β†’ 1 out10.0600 XPM110 B
AeKNrjNj…1NEq95Ta
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.

1.706 Γ— 10⁹⁹(100-digit number)
17067157647052029066…71227814483686737920
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
1.706 Γ— 10⁹⁹(100-digit number)
17067157647052029066…71227814483686737921
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
2
2^1 Γ— origin + 1
3.413 Γ— 10⁹⁹(100-digit number)
34134315294104058132…42455628967373475841
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
3
2^2 Γ— origin + 1
6.826 Γ— 10⁹⁹(100-digit number)
68268630588208116264…84911257934746951681
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
4
2^3 Γ— origin + 1
1.365 Γ— 10¹⁰⁰(101-digit number)
13653726117641623252…69822515869493903361
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
5
2^4 Γ— origin + 1
2.730 Γ— 10¹⁰⁰(101-digit number)
27307452235283246505…39645031738987806721
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
6
2^5 Γ— origin + 1
5.461 Γ— 10¹⁰⁰(101-digit number)
54614904470566493011…79290063477975613441
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
7
2^6 Γ— origin + 1
1.092 Γ— 10¹⁰¹(102-digit number)
10922980894113298602…58580126955951226881
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
8
2^7 Γ— origin + 1
2.184 Γ— 10¹⁰¹(102-digit number)
21845961788226597204…17160253911902453761
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
9
2^8 Γ— origin + 1
4.369 Γ— 10¹⁰¹(102-digit number)
43691923576453194409…34320507823804907521
Verify on FactorDB β†—Wolfram Alpha β†—

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9
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 244201

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 fc1db5bb7ce69016707d4954312dd8613fae3b87e6fb5efb2e55694fac2accb7

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 #244,201 on Chainz β†—
Circulating Supply:57,645,378 XPMΒ·at block #6,800,163 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.
AQZeJoQ81VgeHQBpEYTgvNqV1gnz3L5SvK