Home/Chain Registry/Block #242,786

Block #242,786

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 11/3/2013, 10:25:25 PM · Difficulty 9.9606 · 6,563,226 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
e3055393444b8f0fbe2f9942eabdb09520f4ae29e91d7a79a905ee051fa8b074

Height

#242,786

Difficulty

9.960554

Transactions

9

Size

5.85 KB

Version

2

Bits

09f5e6e4

Nonce

172,996

Timestamp

11/3/2013, 10:25:25 PM

Confirmations

6,563,226

Merkle Root

fbc3264e903e658240c785906e0abad687a5778257ca16f44ba618a2d120994f
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.

5.510 × 10⁹⁵(96-digit number)
55100892282662735752…39010659492052992000
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
5.510 × 10⁹⁵(96-digit number)
55100892282662735752…39010659492052991999
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
5.510 × 10⁹⁵(96-digit number)
55100892282662735752…39010659492052992001
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
1.102 × 10⁹⁶(97-digit number)
11020178456532547150…78021318984105983999
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.102 × 10⁹⁶(97-digit number)
11020178456532547150…78021318984105984001
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
2.204 × 10⁹⁶(97-digit number)
22040356913065094301…56042637968211967999
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.204 × 10⁹⁶(97-digit number)
22040356913065094301…56042637968211968001
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
4.408 × 10⁹⁶(97-digit number)
44080713826130188602…12085275936423935999
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
4.408 × 10⁹⁶(97-digit number)
44080713826130188602…12085275936423936001
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
8.816 × 10⁹⁶(97-digit number)
88161427652260377204…24170551872847871999
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
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 × 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 242786

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 e3055393444b8f0fbe2f9942eabdb09520f4ae29e91d7a79a905ee051fa8b074

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 #242,786 on Chainz ↗
Circulating Supply:57,692,174 XPM·at block #6,806,011 · updates every 60s
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