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Home/Chain Registry/Block #1,368,223

Block #1,368,223

1CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the First Kind Β· Discovered 12/13/2015, 6:10:45 PM Β· Difficulty 10.8364 Β· 5,475,638 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
e9a8d8c7bf7d667ab7c83fd96cfecc64269ebcaf897ca3c257f15aa42ed0f3a1
View on Chainz β†—

Difficulty

10.836386

Transactions

1

Size

200 B

Version

2

Bits

0ad61d69

Nonce

389,505,925

Timestamp

12/13/2015, 6:10:45 PM

Confirmations

5,475,638

Merkle Root

8857025fbdeb3cecbcba9d4d4d129c6e3ef272f19800d8eb86ab54c8a9deb45f
Transactions (1)
Coinbase8857025fbdeb3c…ab54c8a9deb45f
1 in β†’ 1 out8.5000 XPM109 B
ANw2ppbP…TLopjKxk
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.

6.257 Γ— 10⁹⁢(97-digit number)
62573857386969699943…90136139030107980800
Discovered Prime Numbers
p_k = 2^k Γ— origin βˆ’ 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 βˆ’ 1
6.257 Γ— 10⁹⁢(97-digit number)
62573857386969699943…90136139030107980799
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
2
2^1 Γ— origin βˆ’ 1
1.251 Γ— 10⁹⁷(98-digit number)
12514771477393939988…80272278060215961599
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
3
2^2 Γ— origin βˆ’ 1
2.502 Γ— 10⁹⁷(98-digit number)
25029542954787879977…60544556120431923199
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
4
2^3 Γ— origin βˆ’ 1
5.005 Γ— 10⁹⁷(98-digit number)
50059085909575759954…21089112240863846399
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
5
2^4 Γ— origin βˆ’ 1
1.001 Γ— 10⁹⁸(99-digit number)
10011817181915151990…42178224481727692799
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
6
2^5 Γ— origin βˆ’ 1
2.002 Γ— 10⁹⁸(99-digit number)
20023634363830303981…84356448963455385599
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
7
2^6 Γ— origin βˆ’ 1
4.004 Γ— 10⁹⁸(99-digit number)
40047268727660607963…68712897926910771199
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
8
2^7 Γ— origin βˆ’ 1
8.009 Γ— 10⁹⁸(99-digit number)
80094537455321215927…37425795853821542399
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
9
2^8 Γ— origin βˆ’ 1
1.601 Γ— 10⁹⁹(100-digit number)
16018907491064243185…74851591707643084799
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
10
2^9 Γ— origin βˆ’ 1
3.203 Γ— 10⁹⁹(100-digit number)
32037814982128486370…49703183415286169599
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 First 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 1CC formula:

1CC: p₁ (first prime), pβ‚‚ = 2p₁ + 1, p₃ = 2pβ‚‚ + 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 1368223

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 e9a8d8c7bf7d667ab7c83fd96cfecc64269ebcaf897ca3c257f15aa42ed0f3a1

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 #1,368,223 on Chainz β†—
Circulating Supply:57,995,256 XPMΒ·at block #6,843,860 Β· updates every 60s
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AQZeJoQ81VgeHQBpEYTgvNqV1gnz3L5SvK

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