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Block #391

TWNLength 7β˜…β˜†β˜†β˜†β˜†

Bi-Twin Chain Β· Discovered 7/7/2013, 11:57:01 PM Β· Difficulty 7.0133 Β· 6,808,896 confirmations

TWN
Bi-Twin Chain

Interleaved pairs of primes that differ by 2, forming twin prime pairs at each level.

Block Header
Block Hash
84a4373b1f263824cef670c2cfc38390f163e92d008f8e0bd68cc8c0e039d22a
View on Chainz β†—

Height

#391

Difficulty

7.013270

Transactions

1

Size

199 B

Version

2

Bits

070365a8

Nonce

325

Timestamp

7/7/2013, 11:57:01 PM

Confirmations

6,808,896

Merkle Root

3d7e77c2213dc963cab97bf9789b23bf5c8fefd21f980f3790b989cc0b95e12f
Transactions (1)
Coinbase3d7e77c2213dc9…b989cc0b95e12f
1 in β†’ 1 out20.3100 XPM108 B
AGpLwH35…gWJu3vdc
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.

1.159 Γ— 10⁹⁸(99-digit number)
11593973245984668829…52047090041407536650
Discovered Prime Numbers
Lower: 2^k Γ— origin βˆ’ 1 | Upper: 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.

Level 0 β€” Twin Prime Pair (origin Β± 1)
origin βˆ’ 1
1.159 Γ— 10⁹⁸(99-digit number)
11593973245984668829…52047090041407536649
Verify on FactorDB β†—Wolfram Alpha β†—
origin + 1
1.159 Γ— 10⁹⁸(99-digit number)
11593973245984668829…52047090041407536651
Verify on FactorDB β†—Wolfram Alpha β†—
Difference: origin + 1 βˆ’ origin βˆ’ 1 = 2 (twin primes βœ“)
Level 1 β€” Twin Prime Pair (2^1 Γ— origin Β± 1)
2^1 Γ— origin βˆ’ 1
2.318 Γ— 10⁹⁸(99-digit number)
23187946491969337659…04094180082815073299
Verify on FactorDB β†—Wolfram Alpha β†—
2^1 Γ— origin + 1
2.318 Γ— 10⁹⁸(99-digit number)
23187946491969337659…04094180082815073301
Verify on FactorDB β†—Wolfram Alpha β†—
Difference: 2^1 Γ— origin + 1 βˆ’ 2^1 Γ— origin βˆ’ 1 = 2 (twin primes βœ“)
Level 2 β€” Twin Prime Pair (2^2 Γ— origin Β± 1)
2^2 Γ— origin βˆ’ 1
4.637 Γ— 10⁹⁸(99-digit number)
46375892983938675319…08188360165630146599
Verify on FactorDB β†—Wolfram Alpha β†—
2^2 Γ— origin + 1
4.637 Γ— 10⁹⁸(99-digit number)
46375892983938675319…08188360165630146601
Verify on FactorDB β†—Wolfram Alpha β†—
Difference: 2^2 Γ— origin + 1 βˆ’ 2^2 Γ— origin βˆ’ 1 = 2 (twin primes βœ“)
Level 3 β€” Twin Prime Pair (2^3 Γ— origin Β± 1)
2^3 Γ— origin βˆ’ 1
9.275 Γ— 10⁹⁸(99-digit number)
92751785967877350638…16376720331260293199
Verify on FactorDB β†—Wolfram Alpha β†—

What this block proved

The miner who found this block proved the existence of 7 consecutive prime numbers forming a Bi-Twin Chain. 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 7
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 TWN formula:

TWN: twin pairs (p, p+2) where p = origin/primorial βˆ’ 1 and p+2 = origin/primorial + 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 391

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 84a4373b1f263824cef670c2cfc38390f163e92d008f8e0bd68cc8c0e039d22a

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 #391 on Chainz β†—
Circulating Supply:57,718,365 XPMΒ·at block #6,809,286 Β· updates every 60s
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