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Block #243,360

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 11/4/2013, 6:26:16 AM · Difficulty 9.9613 · 6,570,688 confirmations

TWN

Bi-Twin Chain

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

Block Header

Block Hash

7d196937ef3ebce463101ff178ed634d8a428e13e709ec3cb798fd9e974f348c

View on Chainz ↗

Height

#243,360

Difficulty

9.961314

Transactions

Size

228 B

Version

Bits

09f618ad

Nonce

7,676

Timestamp

11/4/2013, 6:26:16 AM

Confirmations

6,570,688

Merkle Root

91707fd6d8c63967ddac95524a497036877d309dde3e85d9784568a21cdcd117

Transactions (1)

Coinbase91707fd6d8c639…4568a21cdcd117

1 in → 2 out10.0600 XPM136 B

AZDUEbdS…RYKMRZET ALfEGCwh…VawujfMm

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.

1.319 × 10⁹⁹(100-digit number)

13197566709937408096…18625806764234208640

Discovered Prime Numbers

Lower: 2^k × origin − 1 | Upper: 2^k × 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 — Twin Prime Pair (origin ± 1)

origin − 1

1.319 × 10⁹⁹(100-digit number)

13197566709937408096…18625806764234208639

Verify on FactorDB ↗Wolfram Alpha ↗

origin + 1

1.319 × 10⁹⁹(100-digit number)

13197566709937408096…18625806764234208641

Verify on FactorDB ↗Wolfram Alpha ↗

Difference: origin + 1 − origin − 1 = 2 (twin primes ✓)

Level 1 — Twin Prime Pair (2^1 × origin ± 1)

2^1 × origin − 1

2.639 × 10⁹⁹(100-digit number)

26395133419874816193…37251613528468417279

Verify on FactorDB ↗Wolfram Alpha ↗

2^1 × origin + 1

2.639 × 10⁹⁹(100-digit number)

26395133419874816193…37251613528468417281

Verify on FactorDB ↗Wolfram Alpha ↗

Difference: 2^1 × origin + 1 − 2^1 × origin − 1 = 2 (twin primes ✓)

Level 2 — Twin Prime Pair (2^2 × origin ± 1)

2^2 × origin − 1

5.279 × 10⁹⁹(100-digit number)

52790266839749632387…74503227056936834559

Verify on FactorDB ↗Wolfram Alpha ↗

2^2 × origin + 1

5.279 × 10⁹⁹(100-digit number)

52790266839749632387…74503227056936834561

Verify on FactorDB ↗Wolfram Alpha ↗

Difference: 2^2 × origin + 1 − 2^2 × origin − 1 = 2 (twin primes ✓)

Level 3 — Twin Prime Pair (2^3 × origin ± 1)

2^3 × origin − 1

1.055 × 10¹⁰⁰(101-digit number)

10558053367949926477…49006454113873669119

Verify on FactorDB ↗Wolfram Alpha ↗

2^3 × origin + 1

1.055 × 10¹⁰⁰(101-digit number)

10558053367949926477…49006454113873669121

Verify on FactorDB ↗Wolfram Alpha ↗

Difference: 2^3 × origin + 1 − 2^3 × origin − 1 = 2 (twin primes ✓)

Level 4 — Twin Prime Pair (2^4 × origin ± 1)

2^4 × origin − 1

2.111 × 10¹⁰⁰(101-digit number)

21116106735899852955…98012908227747338239

Verify on FactorDB ↗Wolfram Alpha ↗

2^4 × origin + 1

2.111 × 10¹⁰⁰(101-digit number)

21116106735899852955…98012908227747338241

Verify on FactorDB ↗Wolfram Alpha ↗

Difference: 2^4 × origin + 1 − 2^4 × origin − 1 = 2 (twin primes ✓)

What this block proved

The miner who found this block proved the existence of 10 consecutive prime numbers forming a Bi-Twin Chain. 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 →

★★☆☆☆

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 × 3 × 5 × 7 × …), 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 × Primorial (2·3·5·7·11·…)

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 TWN formula:

TWN: twin pairs (p, p+2) where p = origin/primorial − 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 243360

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 7d196937ef3ebce463101ff178ed634d8a428e13e709ec3cb798fd9e974f348c

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 #243,360 on Chainz ↗

Block #243,360

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